Pros
Hockeystack has been great so far, I've been working here for an year now. The best reasons to work are 1. Oppurtunity to gather more engineering skills everyday is huge, the product requires solving hard engg problems everyday because of massive amount of data and active customers. 2. Team doesn't set unrealistic expectations ever, rather they help every person to learn and catch up the speed. 3. In my experience, I had a ton of personal / family issues and my manager would always say, "don't worry about work at all, take care of your family first". And this happened multiple times. 4. Every opinion matters, anyone can come up with news ways on how anything should work and they take it very constructively!
Cons
However, there are some downsides just like every other fast paced environment. The engineering team is so small and almost everyone does everything which sometimes causes delay in response / progress of tasks time to time. There can be a lot of context switching because of customer tickets / requests, new feature, performance monitoring. Might not be the best for someone who is looking for stability in their career.