In my experience, it’s fairly easy to judge technical skill. A friendly conversation about technical interests and recent projects can often be enough.
Bullshit. Sounding credible in technical interviews is a skill, not the same skill as actually being a good programmer, and might even (statistically, in the large) be close to orthogonal to it.
We found this out the hard way. At Matasano, we started our work-sample hiring process as a way of filtering out the smooth-talkers. Before work-sample tests, we'd spent loads of time on carefully designed interview questions; interview design was something close to a hobby for some of us.
Of course, it was only after we started doing work-sample challenges that we discovered that not only were a lot of excellent-seeming candidates actually not capable of delivering, but an even greater fraction of the candidates our "friendly conversations" were selecting out were in fact perfectly capable. It was a bad deal all around.
Whatever you do, don't fast-path "senior" developers. Everyone should run the same process for the same job. Not only do you risk hiring people who won't work out, but you're also depriving yourself of the most important data you need to iterate on your hiring process.
It comes down to interest. A good senior got that way because they like solving challenging problems. They are not interested in trendy framework bullshit. In other words talk about the problems and potential solutions. Are things in place to make the job easier? Seniors don’t need easier and this is a huge turnoff.
When I hear companies try to sell me with frameworks and process I know they are blowing smoke. At the very least they are boring and at worst you will be working with incompetent people who are as self-diluted as the company. I agree that filtering candidates is a good idea though.
The reason why some companies cannot figure this out is because they don’t value the problems at hand. They need bodies to put fingers on keyboards and are willing to pay more for people who don’t completely suck. Experience and competence are not the same as excellence but considering the candidate pool I can see why companies compromise on quality.
There are people who can talk through challenging problems at their former companies and how the problems were solved. They can tell you everything you'd want to hear because it's true. Except…they didn't implement it. Maybe they are best friends with the person who did and understand in detail about the tradeoffs and the neat hacks and the insights learned along the way, but couldn't build it themselves.
Those are the "smooth talkers" of the engineering world. Those are the people you can't catch just through a verbal interview.
On a related note:
> If you can’t tell the difference between a smooth talker and strong technical competence you are probably interested in the wrong qualities. I have interviewed enough now to see why some companies cannot figure it out. Ask yourself if you really actually want a senior or a strong junior.
Look at who you're replying to.
I agree with this. I was a hiring manager, and there are those that can really talk technical, in detail. You really think they know what they are doing, how to solve complex problems, how to come up with solutions. You put a keyboard in front of them (or pencil and paper), and they go "uhh, errr, ummm." and fail miserably.
I think until you have interviewed a LOT of people, it can be hard to quickly spot this. Some people are masters at telling you how someone else solved the problem as if they solved it, but they can not solve it themselves.
you can have someone who is a whiz at practical and specific solutions, who thinks critically and analytically and just gets an enormous amount done WELL. And empowers those around them to boot!
they have the reverse problem to speaking about other peolle’s work as their own. instead, they speak of their own work as teamwork.
this effects many great people. also women and poc are particularly likely to do this because they have been socialized to not speak too highly of themselves. “model minority” etc.
if you as an interviewer are already skeptical of what someone says, you will increase false negatives with people who you are asking to verbally “prove” their work and yet have cultural memories of being penalized for “bragging”. they’ll describe a solution and downplay it as challenging or hard because women aren’t likes le when they’re the smartest person in the room, etc.
an interview process should seek to understand many skills: practical, implementation, execution, problem solving, design, high level, communication skills.
a varied process that focuses on a few specific skills, one at a time, is likely to convey the most accurate signal.
False negatives are expected, and honestly probably good overall and in aggregate, because it decreases the odds of a false positive. One of my first bosses that involved me in the hiring process told me one day that the point of interviewing is not to find reasons to say yes, it's to find a reason to say no.
I've seen people that were entirely qualified for the position be rejected at the company I work for because they made some totally understandable mistake - I'm talking about people that took the time off to take a 5-hour on-site coding assignment, and made a mistake but would have had a passing (and possibly good) grade on an academic evaluation.
And now we have 5 open positions and nobody hired for them.
What is your threshold for "a lot"? I have given a few dozen interviews. I always ask at least a couple background questions. The number who even have a polished delivery for that part at all are a minority, and the couple that tried to bullshit me we're painfully transparent. Maybe I just haven't done enough yet.
If you feel that they're talking about a problem someone else solved, ask them that directly. (Did you work with others? etc) If they're lacking on the technical details either it's been a long time ago or they didn't do it.
I would think they and their colleagues discussed alternatives together, collaboratively in for example a Slack chat — so an interviewee can give you good replies about the thought process and alternative solutions that were considered and discarded. I would assume. Or maybe the interviewee him/herself came up with ideas, that his/her colleagues realized weren't going to work, and explained why, for him/her. Then s/he might be really good at describing the thought process.
Basically, they volunteer technical challenges they're aware of while simultaneously telling you what the high level solution is. But then you put a terminal in front of them and ask them to set up Postgres in a star schema with some dummy data, and then to write a query joining the two tables they were talking about before. Despite Postgres being on their resume, they'll completely flounder and not even know they need semicolons to terminate commands. Their joins won't just be wildly inefficient, they'll be syntactically incorrect and refuse to run. They won't be able to create, insert, select, truncate, drop, etc. They don't know how to create an index and can't mention any of the options for indexing, let alone the default provided by Postgres.
Keep in mind this example is just meant to be illustrative. Thinking through how to fix the scenario might not generalize to all the ways this can manifest. The kernel of how this arises is a person like so:
1. They read a lot about technical solutions at a high level. They can follow that if you have problem A then you need, roughly, solution B.
2. They have no contextual flexibility or practical foundation for understanding their solutions. They might have read Designing Data Intensive Applications, but they can't actually code and have never administered a database. To the extent they understood the book, they only internalized low hanging fruit.
3. They are charismatic, or ar least comfortable talking about technical topics. They will try to lead the conversation as much as possible, which is where you see them volunteering technical challenges and then offering solutions. But if you force them to answer heavy technical questions which drill deep into a specific area, they'll probably try to zoom back out.
edit: yeah upon re-reading you’re talking about completely obvious lack of practical experience... fair point
Even though the whole thing could be very simple. Another thing is, they will come up with reasons that the issues with the user story/task for code/solution is due to environment or some other reasons like tools, framework, scalability and "bs".
That's what that asshole is looking for. :)
Though to be fair, if you come up with that strategy and can't do -anything- at a sql console, I'm going to ask how you normally interface with the database, because that's like a Linux expert not knowing how to use tar or ls or something.
As for the Linux/tar piece, I've used Linux on desktop for a few years(both Ubuntu & Fedora) & have used Suse and CentOS for servers for much longer.
I can tell you tar means tape archive. I can tell you I mostly use it with gunzip to compress it. I still google/reverse terminal search what flags to use with it both when archiving it and unarchiving it. I could probably remember some flags if I spent enough time thinking - why would my brain waste that much effort though?
I don't work as a backup administrator. I have better things to worry about knowing/having present at the forefront of my (admittedly human sized) memory.
Do you suppose you could have made this point without calling me a name?
If you can explain how to design a system and you can do it, but don't know the exact commands off the top of your head, my comment isn't describing you. I don't expect people to e.g. know awk like the back of their hand, or to write perfectly compiling code on their first try.
But even if you don't have perfect recall of the commands, it should be pretty clear whether or not you've ever opened an editor and done basic implementation. If the GUI is your thing that's fine. But your knowledge must have some practical foundation which demonstrates you can actually walk the walk.
Imagine you're interviewing a candidate and they're talking through how to design an analytics service. They begin talking about e.g. database architecture, and how this type of data is most appropriate for a star schema. They start talking about the tradeoffs of row versus column orientation. They mention they'll need to do indexing for performance and talk about the index space versus query speed tradeoff. They say they'll do joins on the x and y tables.
Is this demonstrating deep understanding though?
Basically it's like someone else said. They read a book and know a lot of answers, but they can't do the most basic implementation of a solution.
No, it seems about on about the same level as being able to paraphrase the abstract of a paper about the system. I would not take it as showing that someone has read past the first page. A high-level overview just isn't enough for that. You have to ask your own probing questions too. Limiting the conversation to the particular problems they bring up is essentially taking them at their word when they claim to be skilled. I've seen lots of occasions where trying to drill down for a bit more detail on some part of what they talked about consistently came up empty (without going anywhere near sitting down at a computer to write a fizzbuzz equivalent).
Look at it this way. I was able to understand all of the maths proofs taught at my degree, but I could not have come up with them myself.
Imagine putting a math problem in front of someone and asking them to solve it. They correctly identify it as a system of linear equations. They volunteer that they would solve it using x algorithm which has a time complexity of y.
Then you ask them to actually solve it, and they can't even make the first movement towards doing so. They mentioned LU decomposition, but they can't even do Gaussian elimination on paper. They don't know what elementary row operations are. They can't obtain an augmented matrix or put it into (reduced) row echelon form. They don't know anything about linear independence or the rank of a matrix. You put an inconsistent system in front of them and they keep banging away at it, determined to find a solution...etc.
That's what it's like interviewing one of these senior engineers. It's surreal - they confidently pattern match the problem using limited heuristics, and they toss away low hanging fruit to demonstrate knowledge. But when you ask them to do something practical and specific, they either refuse and zoom out into abstract-land again, or they hopelessly fail.
What is system engineering?
It's not just you; the entire IT industry is suffering from systemic curriculum vitae bloat. That's why the working conditions are so bad in the professional sense.
Spoiler: "engineer" as a title for someone who does computer programming and software development without a license is perfectly fine and acceptable in the USA. In Canada, however, it's probably not.
For the record, the National Counsel of Examiners for Engineering and Surveying, which is the US body that regulates engineering licensure and "Professional Engineering", recognizes Software Engineering as a branch of the engineering disciplines:
"Professional (Licensed) Engineer" is not typically used in software development, but if you care about having this credential, you can become a credentialed Professional Engineer in Software Engineering.
Google defines engineering as "the branch of science and technology concerned with the design, building, and use of engines, machines, and structures". An engineer is "a person who designs, builds, or maintains engines, machines, or public works". Software engineers certainly fit that definition from my perspective, because software is a type of virtual or abstract machine.
Software engineering certainly qualitatively feels like other branches of engineering to practice, such as electrical engineering or computer (hardware) engineering. I've never designed a structure, but I imagine the principles are the same: understand the requirements of the customer or sponsor; devise a design that accomplishes those goals within the constraints of the medium you're working with, using principles of scientific reasoning to evaluate what is possible and whether a design will meet your needs.
Last but not least, software can be just as critical to human life and safety as the artifacts designed in other kinds of engineering. (But being critical to health or safety is not a prerequisite for something to be engineering. It's still engineering if you're building a rocket that only robots will fly on, after all)
There may be people whose work on computers does not constitute software engineering. Running some calculations in Excel is probably not engineering. But I think there are plenty of us who build large scale systems that need to operate with high availability under demanding requirements, the properties of which need to be painstakingly planned and analyzed and sometimes mathematically proven -- we who are trained as scientists and engineers, and who apply these principles in our work -- many of us consider our work to be engineering, and consider ourselves engineers. I certainly do.
Simply knocking in a program as a code monkey or hacking haphazardly on a program until it works in some way which isn't formally defined isn't an application of scientific theories in computer science into a practical product, which is what defines engineering.
You have a very narrow definition of the term.
> "Principal engineer"
"Look at who you're replying to." meant "tptacek" or "tyre"? Or both - a general advice?
A certain level of quality is expected, not labeling one selfs as engineers after 1 month bootcamp.
Good point. In many countries getting a degree in engineering takes way, way more effort than in computer science.
Then it takes 10-15 years of work to be called "senior engineer".
Because of this their hiring process was aimed to hire more "strong juniors" even tho they didn't realize it. A strong senior is a person who completely changes how you are even approaching the problem or someone who shows you problems you hadn't seen before. They often see tech in the context of business as well.
As you said, usually, they can't be bothered about learning the new framework of the month or new backend language of the month, but, they have a set of battle proven tools to solve tech problems for businesses.
P.S: I do find it hard to distinguish between bullshit talkers and people who actually get stuff done in the interview process.
Worked at a company which did nightly data imports. Things worked until 'companyx' became a cEient, and the imports were huge. They would take 18-20 hours. Then longer. eventually they were touching the 24 hour mark - unacceptable. Client's data would be more than a day behind. Granted it was a moderate amount of data, but shouldn't take that long.
I was 'new' there - only started a month before - and the rest of the team who'd put this together had been there a year or more. I reviewed what was in place, took a couple of days, and got it down to an hour. Then worked with the existing team and we got it down to under 30 minutes with some tweaking.
I do see some eyes rolling when I tell that, as I know it can sound terribly self-aggrandizing. However, I had a decade of experience at this point, and the rest of the team was just out of college; they'd never faced this problem before. I basically just took the data and imported in small chunks in to in-memory tables (to avoid hitting the disk), and copied those to disk every X rows, and dropped indexes until everything was done. It wasn't rocket science, but did take someone who had a deeper understanding of DB mechanics.
As I'm telling this, I always realize they have no way of verifying this, and essentially I'm just another bullshitter. The more believable I sound, there's an equally high chance I'm either really good, or just a really good bullshitter, and nearly every time, the person I'm talking to has no idea how to tell the difference. It's worse as you get older, because the younger folks just think you're waxing nostaligic about the 'good old days'.
You can't just say "I did X in Y by using Z": you need to begin by explaining that once upon a time there used to be a thing called Y, and on that thing it used to be very hard to achieve X, but in those ancient days there was also a tool called Z, etc.
CBI is a fairly effective technique for general interviewing, because you uncover how people actually behave rather than how they like to think they behave. Most of the gold is in the follow up digging questions, which should separate the bullshit answer from a real one.
I think this is overstated. Disruption for the sake of it is often not that helpful in the context of the business (although, in fairness, you do go on to state they often see tech in that context).
I much prefer people who are delivery focused to those who are overly idealistic or want to change everything out of the gate: a good senior understands priorities and knows when to make a trade-off to live with a sub-optimal situation or solution in one area in order to deliver greater value elsewhere.
Do you have problems to solve or not? Often the problem isn't really a problem, except that your current 'solution' is making it so.
I've untied a lot of gordian knots in my career. It really is a thing.
And if you don't have big problems to solve, why do you want a senior developer then? Just hire a junior and keep on going as usual.
Delivery focus is good, till you realise that it's often just delivering status quo for years on end.
That said, nobody is talking about disruption, just wisdom.
It just so happens, sometimes that wisdom will tell you that shipping shit out the door in the name of delivery focus is going to cost you more than its worth in the long run. Calling them overly idealistic to justify your laziness just makes you look bad.
I'd say a truly good senior can tell the difference between a startup and a mature company and adapt accordingly. It takes one set of skills to ship shit out the door as quick as possible and an entirely different set of skills to come in and clean up the mess the kids left behind.
This is why you are selling. Not buying. Because nobody wants to clean up your delivery focused mess.
Because hiring a senior to ignore the problem is a good way to waste a lot of cash.
I also don't appreciate being called lazy, and especially by somebody who knows nothing about my business or my team.
Please try to keep your tone civil in future.
I didn't call you lazy, I said that shipping in the name of delivery focus was lazy, or at least your argument about idealism was.
Fact is, shipping quality is the far more optimal solution and always will be. Making the trade off and adding technical debt is never a worthy trade long term. The only people who gain from it are you and your team. The rest of the company eventually grinds to a halt and begins taking more and more shortcuts around the code which just reinforces everything in a viscous cycle.
You might find this useful:
I was talking about prioritisation. I am very wary (or perhaps jaded) with people who want to fix everything all at once with no regard to the wider effects on the business of doing so.
I didn't mention anything about quality with respect to what we do choose to deliver, although I can assure you that user experience - of which quality is a key facet - is our utmost concern.
I thought my intent was clear, but sorry if not, and hence my comment about overreading. I wrote very little from which you (and you're not the only one) appear to have extrapolated quite a long way.
That analogy highlights what’s irritating me about this post and this entire thread discussion - there are 1,696 players in the NFL, each with an average salary of $1.9 million. When people talk about hiring “senior engineers”, they behave as thought they’re auditioning an NFL quarterback - the 1 out of 100,000,000 people who can actually perform at that level. For a salary of, on average, about $100,000. When you start out - offering comparatively little but looking for Tom Brady, you’ll pass over pretty much everybody, because the person you’re looking for won’t just not interview with you, they probably don’t exist. After a few months, you’ll relax your standards, and after a few more, you’ll relax them even more and end up hiring a comparative retard like myself - somebody with only a mere 25 years of hands-on development experience and a bachelor’s and master’s degree in CS along with a couple of publications. But if I presented in the first few rounds of interviews, back when you were looking for the guy who could derive the tortoise and the hare algorithm in 30 seconds in front of five people in a boardroom, you would have passed.
To be fair it is environment dependent more than anything else. Forget competence, charisma, intelligence, and everything else about the candidate that could bias their selection and instead look at processes and code already in place the new candidate is jumping into. Does the environment strongly favor original ideas/solutions or does it dictate the narrow acceptance in the most narrow of boundaries?
I have been on both ends of this as well. It is common in software for shops to define success in extraordinarily shallow terms such as whether you are using spaces versus tabs and indenting properly. Another example I experienced last year is whether you should write a giant monster configuration or a small function that receives a single argument. The reasons why shops coat themselves in blankets of code style and configuration is because they typically don't trust their developers and instead strive for a normalized baseline. They are looking for wonderful solutions, but rather task completion.
The lack of conformance isn't necessarily an indication of lower capability, but it is an indication of incompatibility. Competence and conformance are wildly out of sync when the candidate is misjudged relative to the work available. That is completely an assignment failure opposed to a candidate failure. Having gone through this myself it has taught me to ask very probing questions, as a candidate, during the interview. If, as a senior, I can determine I will not be a good fit I will happily disqualify myself.
> A coach like Bill Belichick might have a fantastic, detailed answer demonstrating a thorough understanding of every aspect of football past and present, but he could never make the throw himself.
Would you really hire a coach to be your quarterback? Is that a thought you would really entertain? Even if that coach could do that job he/she would be more valuable doing other work. I would consider this a solid example of interviewer/assignment failure.
Like what questions? I'm assuming the work you're looking for is more along the lines of "wonderful solutions" as opposed to "task completion" - is it as simple as asking, "How anal are you guys about code syntax and whatnot?" and, "How hard are your problems actually?"
Or is it more subtle than that?
What if I were to provide a solution that executes much faster, requires less documentation, passes test automation, and is a quarter of the code but ignores the framework or standard code style?
The standard DOM methods perform thousands of times faster than other options for interacting with markup. I can prove this with numbers. Code like that is not popular. Will I be allowed to write unpopular objectively superior code?
If I can reduce the application build from 5 minutes to 5 seconds will you let me rewrite the build from Java to Typescript?
A/B testing is a powerful way to determine preferential user behavior and a measured increase in conversion. Will I be allowed to write inward facing experiments to test developer behavior?
What if I provide a function as a solution the makes use of scope and nested functions but offers no support for inheritance?
Is it better to complete a task in 1 hour with original code plus tests or extend existing components with risk of regression and 4 days of effort?
There's a great quote from Lou Montulli:
> I laughed heartily as I got questions from one of my former employees about FTP code the he was rewriting. It had taken 3 years of tuning to get code that could read the 60 different types of FTP servers, those 5000 lines of code may have looked ugly, but at least they worked.
Those frameworks and existing components most likely have a lot of hard-won experience embedded in them, and I would be uncomfortable hiring someone who did not appear to understand or appreciate that.
See also: Chesterton's fence.
And I was not being condescending BTW.
> The greatest movie critics probably can't direct or write for crap
They may know a lot about how a film is made. It does not follow that they could sit in the director's chair, or write a decent screenplay. (And yet, they could still be great at critiquing films!)
This is a valid point. Just knowing how something is made doesn't necessarily mean you know how to make it. It's the difference between a designer and an implementer. Or architect and builder.
That last one is a real problem-solving strategy, I can't tell you exactly how to balance a Red-Black tree but I know what a Red-Black tree is and where to look up the algorithm for balancing it and I think that's good enough.
One of the master skills for interviewing is "don't choke." Often good people will make mistakes under the pressure of interviewing and will drop out.
When it comes to a practical session there is the same issue that some good people will choke. Just the sample of who chokes in which environment when is different.
Issues like this turn up in all cases where people try to measure merit. For instance, it is known that some low-SES (socioeconomic status) people will choke on standardized tests like the SAT or IQ tests. It is also known that some high-SES people are as dumb as posts and will have that revealed by standardized tests which are harder to bribe or bullshit.
The hostility towards testing is explained by the combination of those two groups: primarily the Emperor doesn't want you to see they have no clothes, but people have sympathy for poor people.
Too many companies are availability focused instead of ability focused.
The reason? When your processes and engineering are weak, you need people available 24/7 to put out fires.
When I interview for a position, I'm interviewing them as much as they are me.
One of the biggest asymmetries in the whole hiring process, is that of course every company will tell you they have the best development processes, frameworks and code to work on. They may even believe it because they don't know better.
Then you take the job and are stuck fighting fires on a big ball of mud codebase that takes over your life.
If you want to standout as a candidate, try and probe and really find out how good their 'culture is.' Interview them back.
One of the best questions for getting to the real answer is: "What are your expectations for availability?" If they expect availability from you after hours, then their stack is likely unstable because the need availability to keep it running.
If you are lucky enough when you are senior and good at what you do, you don't have to put up with that.
I often tell them about a the third of the way through the interview: "I'm not an availability guy, I'm an ability guy." They often are surprised by the statement. And the discussion that follows it usually tells me whether I want to work for them or not.
What? It requires a special craft to design simpler components. Most of the people don't even see it. This is where your senior skills will shine when you'll make it work like a charm as compared to the previous state.
If you don't see the friction or can't reduce it then please take the first exit out.
The primary difference between simple and easy are decisions. A good senior will spend more energy on considerations for appropriate decisions than the actual work.
This is surprisingly often not understood, even by people I showed the video. And I am not sure why.
But I do think it's necessary in out field to start understanding this much more deeply, especially for senior engineers.
For e.g. - for production deployment, I could either put the entire office upside down. Fires across the departments. Broken applications. Rollbacks. Or, I can automate all of our QA test cases and have a one-click deployment. No huss or fuss. I'm sure after having this experience, someone will definitely say - well, this was easy.
Anyway, good discussion.
I like to state it as complex vs. difficult.
Finding a bug in ten thousand lines of crappy VB code code is 'difficult', but not fun.
Writing an space/time efficient implementation of level set topology optimization is complex.
Senior developers usually love complex problems, but hate merely difficult problems.
What? I feel like you have a very narrow-minded idea of what sr engineers want.
Laziness: The quality that makes you go to great effort to reduce overall energy expenditure. It makes you write labor-saving programs that other people will find useful and document what you wrote so you don't have to answer so many questions about it.
Impatience: The anger you feel when the computer is being lazy. This makes you write programs that don't just react to your needs, but actually anticipate them. Or at least pretend to.
Hubris: The quality that makes you write (and maintain) programs that other people won't want to say bad things about.
(That quoite's originally from Programming Perl 1st edition in 1991, the explanations I think didn't show up until edition 2 in '96 or so...)
Most of interviews I've done to candidates ended up in discussing technology trends and googling around for cool open source projects, libraries and so. This, to me, is a good indicator - as long as you bring them up when discussing relevant problems, this means you thought about a problem and researched prior art to avoid re-inventing the wheel.
Also we tend to end up discussing pro and cons of any given technology and so on. This at the end is a key indicator you're talking to a passionate developer. And passion usually makes someone good at programming.
When it comes to soft skills, usually having such a kind of discussion you can figure out also someones behaviour in most work scenarios (to me, having a good "discussion" mode means you're likely to be fit for team work).
Then I was put in a position to hire backend devs and, even though I couldn't entirely change the format of the interview, I came up with questions I believe could filter out the BS artists/not-yet-good-enough from the talent. And it worked.
Example questions that are truly hard to BS:
1. I want to build a new service that crawls the internet for used bikes and presents them for sale. Roughly sketch out the architecture you would use and how all the parts fit together.
- Why this question is good: it is impossible to successfully answer this question if you don't have experience building systems. Even if you try to BS it, your answer will come off shallow and break under any sort of probing. It also reveals how the dev's mind works when approaching problems.
2. Name your favorite tech stack. What is your favorite thing about it and what is your least favorite thing about it?
- Why this question is good: any dev knows that every tech decision comes with good things and terrible things. I love Python, but GIL, circular imports, shitty deployment/package management, 2.x vs 3.x nonsense all suck. If you haven't been in the trenches, you can't answer this _specifically_... you can only answer it _broadly_. And it's very apparent right away to interviewer.
I had about 4 - 5 of these questions. None of them required a single line of code to be written.
Really? You mean you could memorize a blog post for random languages, go into an interview and answer a question and not completely fall apart from follow up question 1, 2, n?...
You make it sound like I'm asking this question, getting a monologue response and just moving on. These questions facilitate a dialogue between interviewer and interviewee, which quickly reveals your deeper understanding of a subject.
Now, I think your above approach (lookup, memorize, pretend) works great for the kind of technical interview questions that I've been refuting this whole time.
Finally, I don't think my questions are perfect, nor do I think the interview process in general is that great. I think the best way to find talent is to do a trial run for 1 - 2 weeks and see how good they are at taking fuzzy problems and breaking them down into actionable steps, then executing. This is regrettably hard to do for most people and companies.
How do you get people to do a trial run for a week or two?
Most people start looking for the next job when they are already doing their current one. So how can we ask them to do a trial run for a week or two?
Also what about the remuneration(what kind should be given if at all for this period) and does this work for freshers and absolute newbies too?
To me, this is the crux of why I agree with you, rather than the questions themselves. Anyone can rehearse an answer to any question, but a dialogue needs to be created in order to actually find out anything about a prospective hire's competencies.
To be useful, an interview needs to be a conversation, not a monologue.
Except even if you could get someone to do that it doesn't filter for the right candidates. Someone who can quickly get up to speed in a foreign domain is not the same skill as being able to build great systems/code/etc in a domain you're familiar with. The day to day of a programmer after the first X months if the latter and not the former.
Plenty of people can do both or can change from one to another. But it still seems to be that the interview focus should be different as both positions require somewhat different focus.
I don't mind interview having also part where code is written at all. Be it dummy feature or breadth/depth first search or fizzbuzz or any other simple reasonably sized assignment. But in case of senior as in partly decision maker with not much direct supervision in the long term, you need those other capabilities too.
Ask them why they prefer one framework to another.
Ask them how they view testing
Walk through with them on a simple whiteboard problem and ask them where they would write test cases.
Watch for the amount of detail they give you. That will give you an indication of what kind of a developer and how deeply they go into problems.
If their answer involves "well I searched around stackoverflow a lot and asked there" that's a no go for me.
I always sigh in relief when a company I'm interviewing with asks me something like that vs something like "implement x algorithm to solve y niche computer science problem you probably learned in college at some point".
I’ve found that the highest correlation to performance in senior engineers is raw algorithmic skill and willingness to say “I don’t know” when you don’t know.
This is not true of hiring devops or sre’s. For those positions, you want the gopher archetype. This is the person who loves hunting down weird behavior and doesn’t give up when debugging. Let’s be real, debugging is you versus the machine and you’re eventually going to win if you can just be honest and patient.
Hiring senior engineers is really hard, I wish everyone luck.
Neither one is something you want to be selecting for. Some of the best engineers I've worked with haven't had a proper CS education. I've known extremely strong engineers with Neuroscience, Mathematics, Physics and Public Policy degrees. I've got a business degree.
Unless you're working in certain extremely hard (and extremely rare) areas you do _not_ need to filter for algorithmic skill. Most ML doesn't count. Neither does Data Science. In 99% of engineering jobs it's more important to be diligent, rigorous, and organized. (Of course, filtering for those is another issue altogether)
Companies need to understand that not only are they mis-selecting, but they're broadcasting that they're doing so to all the candidates that go through that process.
Approaching candidates with textbook-style algo or data structure questions merely informs that they're going to be working with an educated but overall somewhat junior lot. That's not necessarily always a deal killer, but it's probably not the image that these interviews are hoping to project.
For well-qualified candidates not applying at an industry headliner like AppAmaGooBookSoft, the interview process quickly inverts itself, and it becomes more about the company selling the candidate on their offer than the candidate selling the company on their skillset. Tread carefully.
Do you have any evidence for such a bold claim or is this just speculation?
I bet there's scope to twist it beyond all sensible bounds, and compare the ability of the 99% to the 1%.
I suspect there's top level classical, jazz, and session musicians - who're the industry equivalent of 10x programmers. (And all the other stereotypes probably exist too, I bet there are occasional untrained but gifted musicians who can produce 10x output, but who're amazingly difficult to collaborate with compared to degree level music theory trained musicians... And I bet there are "10 year" musicians with one years experience repeated ten times over.)
The other interesting point there is that probably 99% (or more for, five, perhaps six nines) of "programming" doesn't actually require that much hard-core CS theory. You can get paid well playing covers in bars with a good ear and not being able to read a single note from a chart, just by listening to the originals and copying them over and over in your bedroom. Same as you can make a decent living building basic CRUD websites/apps without having written your own compiler that can compile itself or defended a phd that advances humanities start of the art understanding of something fundamental.
Btw years ago I did work with a top session guitarist (top 10 hits) who after an accident taught himself to program from his hospital bed.
Probably true. But perhaps that could be accounted for in the assessment process. After all graduates from Neuroscience, Maths and Physics degrees have got to be some to smartest people around.
Raw algo quizzing skill isn't necessarily the same thing, though you'd think it was somewhat related because when you're learning to code up "find longest continuous run" you also need to change things around for a bit.
Difference is in real life there's never an end. The algo quiz leaves you at some optimum eventually due to being quite a small thing.
> A lot of coding is simply banging your head against the wall, search SO over and over, changing things around, until it does what you want.
It doesn't look like programming to me. Yes, sometimes we miss something, so our code doesn't do exactly what we want it to do, but when we realize it we just fix the code. This view of coding resembles an improved way to write Shakespeare with monkeys.
I don't find myself in these situations nearly as often as I did back when I was a junior engineer. But damn, I'm sure I looked busier (and more stressed out) back then.
This is not true in my experience. I usually see a strong correlation between algorithmic ability and writing maintainable code. At various organizations I have worked for, I have seen that the ones with strong algorithm skills also happen to be critical thinkers who put a lot of emphasis on simple, elegant, and robust design and code.
So I am very surprised to know that this correlation I observe may not be true in general. How did you come to this conclusion?
The correlation between emphasis on simple, elegant design and code and algorithmic chops is indeed uncanny.
And I'd add "clarity of articulation" to that -- being able to express your thoughts and the problem/solution structure clearly and succinctly is a great indicator as well. Huge overlap with both code maintainability and algo quality.
> raw algorithmic skill
It's been ages that I've been asked anything remotely algorithmic. My interviews are mostly about frameworks, how you fit in a team and whether you know / can be "agile".
Not even a Fizzbuzz, much less so quicksort or more special algorithms.
> and willingness to say “I don’t know”
That never got me anything in any interview/company. To be fair, I found a few smart and cool friends because of this, but they themselves don't look as if they've found a good job either.
Being hired (valued?) as a senior engineer is really hard.
I don't think the number of jobs requiring fairly deep systems or algorithmic knowledge has gone down, but the ratio has.
More important than persistence IMHO is to know when to be persistent and when not, and those two qualities by OP seem to be quite related to it: "raw algorithmic skill" (to know whether something is optimizable or not) and willingness to say “I don’t know” when you don’t know" (seek help, get the right person for the job, etc).
Edit: I know because I was like that in the beginning; it was okay to learn e.g. micro optimizations when learning programming for fun at university, but it'd have been a big issue if I had not been able to correct it.
Someone who is both bright and persistent can move mountains. But it often has a big social downside. People don't like change. Being bright, persistent and also socially savvy enough to sidestep drama is practically a unicorn.
Friday demo day (to sales and cust success and everyone else): "hey everyone, know that thing customer X keep complaining about that we've never been able to solve? It's been super tricky. Just wanted to announce that James here figured it out and it's fixed forever. James you're a hero."
Being good at alghorithms only is great if you work in a very isolated area.
I say a lot of things in the form “I’m a little out of my depth in this subject, but my best understanding is that the behavior should be such-and-such; does that sound right to you?”
I'm assuming you're not talking about spinal cord problems, which is the main search result.
EDIT: found a better source
If saying “I don’t know” and being good at algorithms was enough, you could hire straight to L7 easily or could promote to in a year. Neither of these things happen.
Spoiler alert: work-sample tests are the only practical and generally tolerated one to use (for software engineers) that is actually correlated with job performance.
@tptacek: how do you feel about people who have large amounts of open source work that is easily reviewed? This obviously doesn’t add new data to your company’s test but is definitely some kind of work sample, albeit not necessarily in a similar environment to the one being hired for.
If they want to turn the onsite into one big work sample, by all means, that sounds very effective (and something I’ve seen work well). But in my experience, you’re going to deter qualified candidates by forcing them to do take-home assignments.
But there's a right way to do it: give work sample challenges and then, at least for the most part, end the technical qualification part of your process there. You spend 4-6 hours at home instead of spending 4-6 hours in front of a whiteboard doing dumb coding challenges.
If I was looking for a job right now, I'd probably refuse to interview anywhere that gave me take-home problems that couldn't promise that a strong result on those problems would take me all the way through technical qualification. But a company that could offer me take-home problems and conclusively make the technical part of the decision on whether to hire me based on those problem would be a strong prospect.
I really like it so far. The part I'm battling on it is if the current coding part selects against Java developers. Part of the code we want right now requires a unit test with dependency injection to match an interface. So many of our Java candidates simply can't set up a running unit test. They are used to layers of framework already set up in the IDE and just clicking on stuff. They have full access to Google. Maybe it is good we are filtering out these candidates, but I'm not sure. Still thinking on it.
Yes, it does. And let me put it this way: I've used C# and Java at most of my jobs, those theoretically would be my comfort languages, yes?
I do not use those languages on interviews. I often just use C++ (!), or Rust (free unit tests!) if the company tools allow for it, or worst case I'd learn some Python basics. C#/Java are very awkward and boilerplatey in such a small time frame as 45 minutes.
I've been on the reviewer side of a handful of "choose your own language"-style take-homes recently and found that it's really not good for the candidate if they actually end up using something that wouldn't have been the interview committee's first or second choice. There have been cases where choosing a less-trendy-but-still-totally-viable toolkit has effectively disqualified a candidate, with several committee members not even considering it necessary to look at the code. This is very unfair and lame but an unfortunate reality. I asked that the test be changed to constrain the options at least to a list that wouldn't be immediately disqualifying.
You could advise the candidate ahead of the interview something along the lines of "you'll be asked to write a code sample in either Ruby or Python -- you'll have full access to Google, but you may want to brush up on the basics of these languages if you haven't used them recently".
This does two things: first, it prevents the issue you have, where you're essentially not sure if you're correctly scoring the samples produced. Secondly, it really requires you to constrain the problem to things that someone who has barely used language X or Y can do within 45 minutes.
Ah, but there's the rub. Candidates are trying to please the interview panel. If you don't provide guidance, the odds that they'll just use whatever they think the interviewers most prefer are just as good, if not better, than the odds that they'll actually use whatever makes them most comfortable.
You said yourself that since some candidates pick a language that you don't know well, you can't really tell if the failure of a large number of those candidates is reflective of a bad test or just a mismatched candidate pool. IMO, if you're going to stick to the "pick any language" thing, you should at least find out and ensure that any language the candidate picks will have a fair shot.
> it can even be a better interview because we get more insight on how the candidate communicates and their ability to walk someone else through their solution.
> A potential other bonus is less biases leak through from an interviewer on "that is a strange way to do that in language X."
I would say that if you're worried that interviewers will load in biases toward their preferred shortcuts etc in a specific language, that you should be equally worried that some good candidates are being excluded for choosing the "wrong" language in an any-language-goes test.
Above, you mentioned that there'd be a positive response if a candidate used "Rust, Scala, or a lisp dialect" -- these are all relatively trendy. What if the candidate used nim, Pony, or some other language that hasn't pulled in to the hype superstation yet? What if the candidate used a language that's not-so-trendy anymore, like Visual Basic, Cobol, or bash? What if the candidate used a programming language of their own design, and brought a copy of the compiler with them on a flash drive?
I'm asking because I've seen this in practice. Candidates for a devops position who chose to use bash to implement the very simple take-home task they were given were laughed off by several other members of the interview committee, despite being potentially high-value senior people -- they were at least senior enough that they're more comfortable performing sysadmin-style tasks in a shell, rather than using a massive CM framework or an awkward amalgamation of Python scripts running os.spawn.
It feels like this type of thing happens a lot, in the same sense that very often, "unlimited PTO" just means "guess whatever amount of PTO is acceptable around here and hope you get it right".
I tend to give candidates a simple project already to go, with junit and hamcrest, possibly mockito already available, and ask them to go from there using a provided IDE (which I attempt to get set up as near as they prefer to work as I can). This generally works out fine. I certainly don't feel the boiler-platiness of the language gets in the way, mostly because the IDE is generally capable of doing most of the lifting with that respect anyway, but also because over the timescale of an interview question, we're generally only talking about a couple of classes at most.
For 20% of Java candidates, they do it just fine. Heck, a few echew the IDE and are fine working completely from the terminal (these tend to be particularly very solid at coding). Still wrestling with the idea.
The folks that already work with us (who wrote Java in a former role) see no problem with setting up a project nor do the folks that we hired recently (seeing as they likely passed that technical interview). But that all could be bias.
Maybe you are right. Maybe the next candidate or five in Java will get a base project and we can see how it goes.
I think Java depends much more heavily on powerful tooling to do the heavy lifting, and my experience of using that tooling when I haven't had a chance to configure it in advance has been pretty miserable.
If it's remote, I'll ask them to share their screen with me with a project set up and ready to go, having emailed them a copy of the interface we're going to implement about 30 minutes before the interview.
In general, if I'm asking them to code on my (or the company's) hardware, I'd start from an existing project, if only because I wouldn't expect them to be familiar with the installed tools (oh, you use maven? I'm a gradle user ... etc.) On their own laptop, I'd expect them to be more comfortable.
I'm doing a remote interview on Wednesday. That'll be on the candidates machine (because screen-sharing is easy, getting them inside the corporate network, not happening), and they've been told they'll need an IDE ready to go. I'll expect a project set up and ready to go before the call even starts.
What round is this?
Also, how much of their day-to-day work is going to be setting up new projects? I sometimes feel a better test is to be thrown into an existing code base and asked to make a change. It's far more indicative of the sort of work somebody is likely to actually be doing.
What exactly do you mean by this?
Work sample test fraud is one of those things that sounds like a huge deal on message boards, but when you game through what would be involved in doing it in real life, it makes very little sense.
Talk to them about the code they wrote.
Have a conversation, as if they were already your co-worker, with the exercise as the subject. Go through it, ask them -- non-adversarially -- why they did X, what they thought about requirement 2, how they could get better test coverage for Z. If you see something that seems to be a mistake, talk about it. If you see something awesome, discuss it. I can't imagine someone incompetent being able to bullshit their way through detailed discussion of code they were supposed to have written.
And this provides valuable info about how this person thinks and communicates about the work you want them to do.
I'm not sure why you felt the need to come out guns blazing.
My best guess is that there aren't going to be many companies that will give you definitive statements about what their process will be after challenges who are lying about how they digest work-sample responses. But I don't know and am prepared to be wrong about that.
I was co-owner of a startup at the time, the guy I interviewed called me up and said you did really good but I think you really don't want to work here - my wife said 'Wow, that guy was really smart' considering how some things went later it might have been better if I'd said no I really really do
This is why take-home problems are almost completely irrelevant except for filtering out good candidates. Eventually those problems optimize for perfection which help out those who 'cheat' at the process and people that otherwise put in earnest efforts are rewarded with denials. This is something I've experienced before in my job search where I would put in an honest effort and get 90% of the problem solved, but get denied because my solution wasn't flawless.
So allow me to call bullshit on your own claims that this is the right way of determining technical qualifications.
Not all companies handle it like this. I had a take-home exercise as part of an interview last year. I hit a real snag on a fairly small part, I couldn't figure it out, and I ended up leaving a bug in my submission because I simply ran out of time. Very frustrating.
It was raised at the interview; I admitted that I knew it was there, and that I hadn't been able to figure it out. We discussed possible causes: it actually turned into a pretty interesting, though minor, technical conversation. The interviewer eventually told me that he had figured it out after a little investigation (and I expressed my gratitude for the explanation!)
I ended up getting an enthusiastic offer from them.
It's possible that the company stated the take-home work in terms of non-negotiable deliverables, and their baseline for allowing a candidate to move forward is 100% of those, and they prioritize candidates who take initiative and do more work beyond the base requirements.
... not that I would agree with such a process (it biases towards people with more free time, like people with fewer dependents and people who are currently out of a job / underemployed), but it's very possible that this is what you faced.
As a new immigrant, my wife had trouble finding work as a designer until she was given a take home work sample test. After that, the company that gave her the test hired her quickly and she has been doing well with them ever since.
I’m currently doing the gauntlet thing myself, but none of the interviews I’ve done have asked any technical questions pertaining to the role that they actually want to hire me for. It’s all generic stuff that frankly I would have done better on 20 years ago.
Surely most people would prefer this to whiteboard tasks?
Then I was hired under probation, as everyone there was, and the understanding was that I could be easily dismissed if it was clear that I wasn't working out.
It's rare that people fail probation; so long as you apply for work you are actually capable of doing...
Myself and a co-worker were once let go for "performance reasons" at 10 months - just after project completion (successful). It was beyond my probationary period, and no issues where raised in the 2 performance reviews.
Their notice period was just 1 month. We were effectively cheap contractors.
My advice now is to treat offers with a low notice period (of them telling you) as a red flag. The norm is 3 months, after probation.
Yes, above a certain size, companies typically have some formal procedures. But typically those are a fig leaf.
In many labour markets, there's a legal 90-day probation or equivalent. You bet your boots some people get dismissed at 80 days. Or the job was contract-to-hire, and the contract doesn't "get renewed".
But on top of that, literally every company I've worked at or any of my friends have worked at (including lotsa startups, two of FAANG, and some in-betweens) will terminate when they want to terminate. In most non-European labour markets that I'm aware of, there's a penalty for doing so, and the company just pays that penalty and gets on with it.
Sometimes there's more security than that, I've heard (but not experienced). And sometimes the company puts in large effort to cultivate the underperforming employee first (had that happen to me once; they tried and I tried but it didn't work out). But the overwhelming majority of cases of my first-hand and second-hand experience, dleslie's summary is about the whole story:
> The real interview is always the work you do
Thus, probationary periods can be a time of training and growth for the new employee.
I suppose you do sort of feel a little stressed during the trial period but I've never seen anyone fail it and it applies at every company, so there's no escaping it anyway. When it was introduced some people got quite upset but I can't really say I think it's had a bad effect.
I guess from the companies perspective if they realize they made a grave mistake they can back out of the hire, but they are still very careful and rigorous in the hiring process just like always. It also allows the candidate to bail if they realize the company wasn't what it said it was. It goes both ways. Again, in practice it seems mostly harmless.
Perhaps the US wouldn't do so well with a similar policy maybe even just due to the crazy healthcare situation going on over there. I couldnt say.
I'm not sure what you mean by "it applies at every company". Getting hired and then fired a week later is virtually unheard of. This is not a fear I have, at all.
But if you told me it's probationary, that is totally a fear I'd have, I'd get paranoid, so I'd rather work somewhere else. You're basically telling me it's not a real offer in my eyes, and I should not expect stability.
> Again, in practice it seems mostly harmless.
It's extremely harmful in a place with poor labor protections that is the US, for reasons that I don't feel like expanding on and that you can educate yourself on if you wish.
Not everyone likes it or agrees with it, and I can only comment on the software industry here and not other industries but it's not the end of the world and the sky doesn't at all fall. When they introduced it a lot of people tried to make arguments like it would be abused etc and as far as I can tell there hasn't really been any drama. YMMV depending on country.
What clicked was I was finishing their sentences and knew precisely what they were asking. It was an incredibly rewarding experience which led to a same day offer.
Ideally you would be given guidance on what they will judging you on.
Then they said my work sample was amazing, and they’d like to do an on-site Q&A about it, but when I arrived the engineer hadn’t even seen my work, and proceeded to just quiz me on obscure JS trivia.
Which I promptly failed.
They then rejected me even though they were happy about my work :/
Six hour take home tests is fine, but I want $1350 for that in advance as a consultation fee, and if I hit 6 hrs and it's not done yet they can keep paying until I am done or we can just end it, no refunds.
The idea that I should spend six hours doing free programming for random companies that say they are desperate to find anyone qualified is absolutely absurd and insulting. No one should put up with that, particularly anyone with an established and verifiable career.
It's employment, not marriage, guys, lighten up with your strenuous and time-draining processes. We senior employees aren't as, is the word excitable, as the entry-levels about joining your workforce.
The elitism of some engineers is mind boggling, instead of being grateful working in an industry that has so much demand that you can easily find a job at anytime, you complain about the process being insulting to your oh-so-important persona.
If i really want to work for a certain company because what they are doing excites me, then yes, i'd do a 6 hour take home test where I can probably also learn a thing or two and I am willing to bet a lot of other developers would too. As an interviewer, someone charging >$1000 for a take home test would be an immediate red flag and our mindsets probably don't match up.
If this works fine for you, kudos.
I'm not the guy who says he should be compensated for take-home tests above. I am however a senior engineer. I'm spurning any long interview processes because they cost money. I don't think it's entitlement, but if that's what you want to call it, so be it. It's called hours worked, hours paid, and in the West it's been a concept since at least the 18th century.
Individual consultant: loses 5 hours of interview time (and commute time) or take-home exam. Let's call it $800 for the sake of argument.
Company: loses 5 hours of interview time, plus the time it takes to "quiz" the exam.
Individual loses money that he / she uses to pay their mortgage.
Company loses profit because the time spent interviewing the candidate could have been spent working on feature Y of the application. So shareholders / VC's lose.
So you're saying it's fair that the individual contributor who loses half a day's pay in your interview process is equivalent (you DID use the word "fair" so that's an equivalence argument you made) to a company's loss of a few hours out of the many thousands of man-hours they rely upon? It's a .0001% of their profit, assuming the employers don't work a few hours more to make up for the lost time, because they will (they're salaried!)
But I have 0 tolerance policy towards puzzle whiteboarding tests. It is total waste of time.
Large companies are not "highly incentivized" to optimize they're hiring process. Once a certain throughput is achieved, there's very little reason to revisit it, because if they revisit it, "they're lowering the bar", or not "optimizing for recall" or whatever.
Mindlessly copying large companies isn't all that useful. Microsoft famously loved brain teasers. Can't get the fox, chicken, and grain to the other side of of the river? You must not be able to code either. Google, loved asking your SAT scores because, "obviously" someone that got some arbitrary score on a standardized test, a minimum of 6 years ago, certainly means something today.
Large companies aren't immune from bullshit. In fact, they have the habit of metastasizing bullshit, because of "Well, X does it, so it must be good." X only does it, because they had a stupid idea, became successful because of completely unrelated means, and then fooled themselves into thinking their process was good, "Well, I've been hitting candidates with ball-pein hammer for years, and I'm successful, so screw you."
Interestingly enough, eventually both Microsoft and Google abandoned these interview questions, because eventually, they realized that one had nothing to do with the other, but only after years doing it, and others copying them.
The problem is that requiring IQ tests for employment introduces liability that employers do not want.
Neither IQ nor SAT scores correlate with job performance. SAT scores were requested at Google for years. Explicit aptitude tests have been used in the past, and continue to be used. They are quite legal, as long as they are used for their intend use.
SAT is an IQ test:
The TL;DNR: Nuh-uh!
In the future, you really shouldn't link to dueling articles in an opinion section. It makes this all too easy.
Why do you think they are incentivized to get studied? If anything, power dynamics in large hierarchical organizations keep away any studying done that can threaten the power. Sometimes studies do happen though, but large organization can never apply the results to anything on their scale. They are more worried where to even get such massive stream of professionals to hire.
Also have you got any examples of this research that actually proves this correlation I haven't heard of any and I would have as I have spent decades semi involved in IR (industrial relations) in the UK