Pros
Worked with the smartest people I’ve encountered in my career. Perks are amazing compared to most companies, but not competitive with their peers so getting the best talent is difficult. Open heads are open for a long time, and lately have been hiring sub par. You stay for the people and the mission.
Cons
If they stay for the mission and the people, they leave because of their managers. The reviews about nightmare HR and politics are very real. Little opportunity for upward mobility. And there is NO accountability for managers - no incentive for them to be good managers and no way to correct their behavior. I do recommend working here ONLY IF you are confident that your manager has a good track record and that you are positive you want to work for them. Do not overlook this for the sake of working at Twitter.