Pros
We focus on making the users life simpler and are trying to build a company that makes money because people pay us for what we offer, which is fairly unique in this day and age where most companies are focused on eyeballs to show ads. We also solve challenging technical problems at scale both on the client (large amounts of personal data, in fast low resource clients, across a wide variety of platforms) and in our backend (large amounts of data, mostly unique per user). And when we build things we strive to build them correctly. Both because we're protecting data that is precious to our users, but also because we believe in quality and things just working for our users. Benefits, time off, etc are all world class; but they're not the reason you should work here. The reason to work here is the focus on the user, the focus on quality, and solving hard engineering problems.
Cons
The company is growing fast, and growing causes pain. Medium term goals change more often than at a big company or than they would if it was a less competitive space since we're always trying to balance being nimble without getting distracted. It's part of the fun, but it can take a little to get used to.