Pros
Peek has an awesome collaborative environment. After just a few weeks, you'll notice a very strong bond between yourself and your coworkers, so it is a great community, and you definitely feel like you're in the trenches together. As some mentioned, it's a fast-paced startup, so you will be working closely with pretty much every group (if not all groups) at some point or another.
Dinner is served most nights (M - W when I worked there), and there are "Peek Academies" (similar to a lunch and learn), in which CEOs and founders of other companies come in to talk about the trials and tribulations of launching a company. There are also lots of outside team bonding activities (scavenger hunts, etc...) that are a lot of fun.
I'd have to say that I definitely would not have gotten my post-Peek job without my experience at Peek. In a little over a year, I definitely learned more than I have at any other job in the past, and I feel well-set in terms of professional trajectory.
My boss and peers were amazing to work with and were always there if I needed to voice any concerns or issues I was having. Your work has a direct impact on the company and achieving strategic goals, which is great.
All in all, a great startup that's growing like crazy (every time I visit, there are loads of new faces).
Cons
As mentioned, it is a very fast-paced startup, so the hours can be quite long. I wouldn't say that it is any more extreme than any other startup of the same size. Many nights, you'll find yourself working at night with your coworkers, so it's a very roll up your sleeves type of environment. I'd say that it just depends on what you're looking for in terms of work/life balance.
