A few times a year there may be a crunch time when people work longer hours and maybe come in on the weekend, and I strongly advise stepping up at those times or you'll take a serious social hit.
The 60-80 hour work weeks that people speak of are actually quite rare. A few teams and a few very motivated people work that way, but most don't.
I'm in Argentina btw.
The team was expected to generally work well beyond "9 to 5" and work / be available for calls on weekends.
Long story short, I no longer work there. As a young developer I did learn a lot though.
In hindsight, I'd worked at three startups in college prior to this job (in Austin and Boston) and I think it boiled down to my boss being an incredibly smart well intentioned guy, but he just couldn't manage people nearly as well. I was mostly turned off when we'd work so hard that we'd miss possible problems or build features we didn't need that could've been avoided by simply taking a step back and maybe thinking about it for an extra day.
What are the typical work hours in a large tech company in California?
Very few require more than 50 hours a week. Typically people are in office 7-8 hours a day, and often put in some time handling communications or catching up on small sums of work in the evenings.
Folks in higher management positions (directors and above) typically work more in a company like this. The demands on directors and above in tech companies are uncharacteristically high.
What about medium sized companies with less than 300 people?
This starts to get into the "it depends territory." Companies this size are small enough to still become reliant on extraordinary effort from individuals. Being a manager is often very stressful in smaller-but-not-small companies like this because you're always juggling resource scarcity.
Engineers should expect 8 hours a day, but occasionally much longer. This kind of company is often not-quite-there-yet on having well-managed infrastructure that doesn't page you at 3am.
What's it like working at a very small startup when I'm not in the first 3 employees?
You can tell if it's going to be more-but-okay (50-60 hours a week) or unsustainable (70+) by talking to the founders. Most small venture-funded companies will optimize their hiring around single people willing to take long hours for less pay and the hope of a payout.
What's it like founding a company?
It is what you make of it. You absolutely should expect some absolutely booked weeks. It'll be awful. It may or may not be worth it.
In summary: the larger the company the more time upper management will put in and the more normal hours everyone else gets to work.
I think the hours that work for you really depend on how much time you need to be by yourself. If you're busy with meetings during the 10am-4pm hours, then maybe you want to get in early at 8am or leave later at 7pm so that you have some alone time to get work done without being pestered by others.
I contrast this experience with my jobs in Chicago and Atlanta, where 9-6 was expected, and if you showed up late you would get in trouble. I haven't really experienced that in SF or SV, unless there was a 9am meeting that I missed because I was late. (Hasn't happened yet, but it's the only reason I would get yelled at.)
At a prior job it was flipped - most nights a few hours an evening to talk to India.
I haven't had a silicon valley job that encroached on dinner on a regular basis, but part of that is how I selected the firms.
35% of people eat in "subsidized" onsite or on-campus cafeterias and foodcourts. This tends to include Microsoft, Amazon, and Apple.
15% of people will go to local area eateries, grab their food to-go, then return to the site to keep their time offsite to a minimum, then eat at their desk. Personal orders to Grubhub, etc. fall in this category, and this category is growing.
15% of people will go to area eateries, dine in. These tend to be upper management, as it's easier to argue that it's a working lunch.
15% skip all meals or snack on food brought from home.
If you're making $80/hr., a one-hour lunch break unpaid makes your lunch about $100, so it's a very expensive decision to take a continental-style lunch offsite.
If you think as a big part of your job, your employer derives a free benefit from your time spent offsite. If you lose focus by spending time offsite, your employer derives an expensive benefit by feeding you free lunch.
1 hour lunch break is often encouraged by employers. Working as a freelancer I work an "extra" hour, because of my lunch break. So do the employees here.
* Me: 8ish to 6ish
* Eng 1: 930ish to 630ish
* Eng 2: 830ish to 630ish
* Eng 3: 1030ish to 730ish
* Eng 4: 8ish to 6ish
* Eng 5: 830ish to 630ish
* Eng 6: 830ish to 630ish
But the team skews a little older and a little more settled down.