I've heard a lot of bad things about the culture there. The main complaint I've heard is that the company sometimes organizes new projects in a directly competitive manner: multiple internal teams will be assigned the same project and given the set of criteria for evaluating the work. Then at whatever deadline, only the team that "wins" gets bonuses associated with that work.

It may not affect open-source teams though, only the finance side, and it could have changed since 2014-2016 when some of my former colleagues were there.

I also think it's telling that Wes McKinney decided to create Ursa Labs. I know Two Sigma is partnering in the early stages, but I read it as clearly a sign that he wasn't empowered with whatever he was promised by them.

I have friends that work there. They say it's great but at times it's ultra-competitive..