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How I Develop Things and Why (kennethreitz.com)
202 points by jorde on Jan 27, 2012 | hide | past | web | favorite | 33 comments

> Before I start writing a single line of code, I write the README and fill it with usage examples. I pretend that the module I want to build is already written and available, and I write some code with it.

I write the same way. It forces you to think of how intuitive and natural your code should be. I've run into so much code that makes me wonder, "did they even consider how someone will want to use this?" Software should resonate with how people expect to use it, coming in with little-to-no understanding of the actual implementation.

This is very important, but he's making a deeper point, that the README ties it to the problem it solves. It's possible to make a beautiful, intuitive, natural solution that nobody needs (not even yourself). From the user to the code, it goes:

  problem -> usability -> code
Although intriguingly, pure mathematicians create solutions for their own sake (without reference to a problem), and it sometimes (often?) turns out to have practical application anyway e.g. http://en.wikipedia.org/wiki/G._H._Hardy#Pure_mathematics

BTW: I just noticed you can resize the reply textarea by dragging the bottom right corner. There doesn't seem to be any JS or CSS in the HN source to do this, so I guess it must be in Firefox 9; google says chromium has it too. Seems about 1.5 years old :(

Pure mathematicians are always motivated by a problem, even if it isn't a "real world" problem.

So might they too fall prey to the same issue, of losing sight of the problem they are solving?

i.e. that the equivalent of a README would also help pure mathematicians? I guess that would be a statement of the problem: a formal definition of assumptions, and the outcome (if possible). Though I think getting to that point would be where most of the work is.

reply your BTW: modern browsers support that feature, it could be altered by css code:

resize: none | both | horizontal | vertical

many browsers use both as default

Commonly called use cases. http://en.wikipedia.org/wiki/Use_case

I don't have a particularly favorite ideology or process myself but the important think is THINKING about the software you are going to write BEFORE you write it. To that end use whatever works.

If you need a formal process involving use cases with a specified and standard format great. If writing the README does it for you then more power to you. The important aspect is the thinking.

I write the tests first which is kind of the same thing except that I can actually execute that API and see if what I wrote actually works.

Writing good tests first also helps me constrain my implementations to be as simple as possible as well. Otherwise my tests get hard to write and that's a sign things are probably going in the wrong direction.

Often though you can't have your cake and eat it too. There are two schools of thought: worse is better and the right way. The former way eschews simple APIs for simple implementations. The latter is pretty much the opposite.

I'm currently working on a project where I'm trying to maintain a simple API across three different, related services. One of those services has such a simplistic interface that maintaining the simple API that the other two have has made the implementation comparatively complex.

Now I have to take extra care to make it as simple as I can... but it's still complicated. Which means my poor future developer who has to maintain this thing will need lots of documentation in order to understand it (fortunately I maintain TODO lists and notes as I go to accompany my stories... forming a sort of journal of my development process for each project; it makes it easy to pull out useable "how and why" documentation).

No, written tests first means you make the code easy to test. That may make it easy to use to, but it is not likely. Easily testable tends to mean that the class knows to little. And as a user that you have to tell it too much.

> Easily testable tends to mean that the class knows to little.

No it doesn't. You've got a pretty big job proving that ALL TDD does that.

Have you ever read python doctests? They are a perfect example of tests that describe both functionality and usage.

I said tends to mean. That does not mean that it is true all the time, but that, a priori, it is the most likely outcome.

The problem is that the worse is better school usually wins over the long run. Jamie Zawinski has a great essay on this [1].

Unix was a "worse is better" MULTICS. DOS was a "worse is better" CP/M. Windows was a "worse is better" MacOS. The advantage of simple implementations is that you can get them in front of users right now, and then iterate your implementation until you have something that's cheap and adequate. Not perfect. Not even great. But adequate. However, as the essay points out, cheap and adequate today beats pricey and perfect tomorrow every time.

[1]: http://www.jwz.org/doc/worse-is-better.html

> Windows was a "worse is better" MacOS

Bad example, MacOS was out years before windows. Microsoft just got a massive market hack. It had nothing to do with solving a problem directly and then iterating...

MacOS (not that it was then branded as such) - 1984. Windows 1.0 - 1985. So not quite years really.

Windows 1.0 was just a fancy dosshell. Windows 3.0 should count as 1.0 in this case I think :)

Frankly I think you could make an argument even Win3 wasn't all that much to write home about....

(I confess to still mild incredulity that MacOS beat AmigaOS so thoroughly in the market, being both more expensive and substantially less powerful in both hardware and software. If Commodore had done their jobs properly, we'd be saying Steve Who?)

january 1984 vs november 1985... you going to get pissy about 3 months?

My point is still valid.

It's by Richard Gabriel.

It kind of reminds me of an interview with Larry Stroman. He was a comic artist that I really liked on X-Factor and someone asked him how he approaches drawing a comic. He stated that he actually starts with the very last page and then goes back to the beginning to work his way there.

I've started following this rule for all of my personal projects. However, many of us find it difficult to apply this rule to the software we write on the job. Most of the projects we work on aren't for us. They are for customers with vastly different needs. When you are creating that type of product, I don't think this rule really applies.

Writing use cases and thinking about how the user is going to interact with your system is a very large part of creating correct and defect free software. Besides the obvious "will the user get it" it has a huge benefit when it comes time to design of your test suite.

Consider an imperative programming language where you can have null values. A null value most often means that some piece of data is optional or not required for operation. One example of this could be a form field for users to enter their real names. If you're making a social site ala reddit or something else you might want to make real names optional. Hence when someone fetches the real name field or passes it as an argument to another method it could be null.

Designing the use cases will help you because when it comes time to write the implementation and test cases you have a concrete understanding of why the value is null. If your program is sufficiently complex this real name field may end up being passed around to several seemingly unrelated modules. Having the use cases drawn up prior to implementation will help you quickly diagnose those crashes or null pointer exceptions and more generally answering the question "Why is this value null?"

Edit: Ineligibility ++

Or obviate all of the potential downfalls with null by simply sticking "anonymous" in the name field.

Nailed it. I've been very guilty of writing applications and APIs strictly oriented towards my own understanding. Also, I like how you throw a jab at all the BS metrics companies use to try and come up with a useless startup they can flip. ;)

It's always great to be reminded to step away and remember why we do what we do, it can easily be lost in the complexity of problem solving. Nice article.

This is basically customer testing, except treating yourself like the customer. This can be a good starting point, but is also dangerous for a multitude of reasons you already know and I won't reiterate. It's a good way to get started thinking about your solution, but does not replace talking to real customers whose problems you're trying to solve.

There are lots of ways of doing things, and more than a few of them are sensible. Without zeroing in on a specific well-defined problem, you usually won't have any hope of identifying anything like 'optimal' solutions - let alone uniquely optimal solutions.

"user in mind" and "have a real problem" and "get things done" and "responsive design" and "designed for Humans" and "make it happen" and "never compromise the API" are vague platitudes which don't even provide interpretable advice, let alone specific usable information.

It can be slightly obnoxious when a battle-hardened grayhair begins to hold forth on vague general principles in this way - it can still be productive to listen insofar as knowledge is being shared. What information is being shared here, and what experience or reasoning is there to ground it as knowledge?

I'm not sure if this principle is a good one for starting a business. Many of us aren't exposed to meaningful problems outside of coding, using the internet, etc.

> Many of us aren't exposed to meaningful problems outside of coding, using the internet, etc.

Are you certain? Unless you live at home 24/7, you're interacting with the world every day. If you're like me, you regularly run into situations that are "sub-optimal" in terms of how much hassle you have to deal with to get things done.

I think the key is to stop thinking that meaning problems only exist in the realm of computers. In fact, most of the meaningful problems in our world are outside of the realm of software precisely because no-one has looked at the problem and thought "hey, software could make this easier".

An example we're all painfully aware of: medical records. There's a TON of paper involved, little co-ordination between doctors, the list goes on. People are working on the problem, but the revolution hasn't arrived yet.

A different way of putting it comes from Paul Graham: "don't think that you're trying to start a startup, instead think that you're trying to solve a problem".

Well, ok, let's talk about medical records. Not many people have the expertise/knowledge to tackle that issue (they can acquire it). They're not around doctors, and healthcare to experience the pain point and understanding the nuances of tackling that problem.

On the other hand, based on our daily interactions, we're more predisposed to making a better Javascript framework, developer tools, better ways of managing our social contacts, etc.

I didn't understand the responsive design analogy. I assume it's not the operating system that the developer responds to, so what is it?

The problem.

I don’t think the analogy from web design carries over, then, does it? You’re not using the word "responsive" with the same connotation.

Sell first. Build later.

^^^^^^^ This. It is so important to be a great idea salesperson. Even if you are writing a OSS tool, if you want contributors you need to sell the idea.

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