Pros
These are some of the smartest people in software I've ever seen. They work hard, they work smart, and everyone executes at a high level. The CEO is a curious guy who seems to be getting great advice from his mentors and making excellent decisions related to recruiting and delegation. Product and engineering ship releases at lightning speed, and customer retention is airtight. Mostly everyone in sales does well given that they are selling best-in-class solution. If you've worked in other startups and were the best in room at what you did, you might be average at Amplitude. I was impressed with the quality of work that everyone did there. Food perks, location, and office vibe are great.
Cons
Culture is not as transparent as they emphasize. There are a handful of people in management on the GTM/customer side that are legacy hires or yes-men that could/should be replaced with people that have more experience. These cons shouldn't outweigh anyone considering working here. Beware the lower level sales management, and figure out why people got let go in the past to avoid making similar mistakes.