I was 37 when I joined Google in a senior IC role in 2008, so nearly my entire 40's. It's still work, there are still issues with coworkers and there's still stress compared to the startups I used to work at. The company isn't going to go out of business but you can still get a manager who doesn't communicate well and gives you bad performance reviews as a result. Google turns over more employees in a month than the entire headcount of some of my previous companies. And GOOG is a huge company - if anyone says it's either great or horrible that's probably true for them, but it doesn't mean much for what your experience is going to be. I honestly don't think that being young is really much of an advantage one way or other here - there are successful people in the 40's here, even ICs, there are a lot of new grads who wash out after a year or two and go elsewhere. Big companies have much more idiosyncratic tech stacks so knowing any particular technical skill isn't that huge a deal as we probably don't use it anyway. Know the basics, know how to write, know how to manage up.
edit: reading some other comments I think it's easier to be an older IC at big companies than startups/small companies. But whether you should pursue a management track is a completely different question.
edit: reading some other comments I think it's easier to be an older IC at big companies than startups/small companies. But whether you should pursue a management track is a completely different question.