I've joined Google 4 months ago, and so far it is the most enjoyable job I've had, including grad school. I've worked at 3 start-ups before, and after working a

I've joined Google 4 months ago, and so far it is the most enjoyable job I've had, including grad school. I've worked at 3 start-ups before, and after working at Google, I think promise of future riches is the only reason to prefer a start-up. If you are proactive, you get full freedom to choose problems you work on, a ton of computational resources and many very smart and supportive people around you. I had an opportunity to join Google earlier as a "general pool" SWE, and I turned it down because I thought I might get stuck maintaining some boring piece of code. But if I knew what I know now, I would've taken it and would probably be in the same position as now -- SWE's have ability to reallocate themselves, and if you find a better team, your old manager isn't going to fight to keep you