Pros
Smart people in the valley are relatively common, but it's hard to find companies where people are not only brilliant, but also work exceptionally well together to get stuff done. Everyone brings their A-game to work, and we band together to achieve some pretty incredible goals. While the work can be pretty challenging at times and there have been some late nights as a result, overall it's been inspiring for me to work here and be part of something that I think is really special in the valley. Sometimes it gets so busy that I forget how much we've accomplished in such a short amount of time. But when I look back and see what we've pulled off, I'm blown away (it also helps that my friends who work at larger and older companies point out that we've been able to do some pretty impressive things for a much smaller and younger company).
Cons
As we've grown rapidly, many teams and individuals (me included) have seen our roles change and evolve as the business needs shifted. I'm not surprised by this of course; I joined a startup to learn a lot and grow with the company. But while I like the challenge and the way it's pushed me to learn new things, it can be draining to keep up with the pace of it, especially as the business never seems to slow down. It's clear though that some folks we hired in the early days aren't able to keep up with the change in their roles and are having a really hard time keeping up. In ops, we hired a bunch of people for QA, and several of them have not been able to adapt to the changes in their roles. A lot of them have been pretty mad / pessimistic and vocal about it, which has been a bit of a drag. I hope they can find something they like better and move on.