Pros
Video compression is an interesting and challenging topic. You got to work with the biggest customer names in the industry. It's an opportunity to work with some of the smartest engineers in town (and beyond). The workspace is nice with many collaborative spaces.
Cons
Now that all Elemental cofounders and many former execs and old timers are gone, this company has become just one cog in the big Amazon machine. Senior management lacks experience and is ostentatious against engineers who have been with Elemental for many years. Guess what? Elemental was acquired because of the expertise in video we could bring to AWS. The new management team tends to forget it. Work-life balance is non-existent. You will get paged at any time, including nights and weekends. You'll constantly be asked for more by your manager. And don't imagine that it is a stepping stone to a promotion: the chances are very thin, especially when you are based in Portland. Seattle is where everything happens now. As several others mentioned, many perks have gone away. Friday lunches are still a thing, but for how long? Motivation is following the same path - you can tell when you talk to people in the office. Sad times.