Pros
In general, there seems to be a strong company-wide sense of inclusion and empathy, which really makes Twitter stand out. People are very passionate about the role that Twitter has in society, and while there is constantly a lot of public backlash towards the leadership around critical decisions, internally, I think that there is a lot of trust in the expertise and intentions of other teams. As an engineer, I feel empowered to work on projects that I think are valuable and interesting without feeling entangled in internal politics. Twitter was one of the first companies to really devote themselves to WFH, and the transition was essentially seamless, since Twitter was already shifting towards remote work. In addition, there are "Flexible Work" opportunities, where employees can request to temporarily or permanently work out of approved locations, which is quite amazing.
Cons
There are frequent re-organizations (every 4-6 months?), and while you learn to roll with the punches, it makes it difficult to plan out longer term projects, since staffing & priorities end up changing. You end up having a handful of half-baked projects that die after one or two iterations.