Pros
Good vacation policy. Nice office. Snacks. Good work-life balance. A lot of freedom and autonomy in managing my responsibilities. Exciting work to be done. Smart colleagues.
Cons
Although it's a startup and you'd think there's room for growth, it actually often felt like there wasn't room for upward mobility unless you were part of an "elite" crowd that somehow got on the CEO's good side. You can ask your manager about it and have them assure you that they want you to grow at Datadog, but then nothing would happen (even as you took on more responsibility and proved yourself time and again). They'd cite policies and rules about why things had to be a particular way, but EVERYWHERE you turned, there would be exceptions to those rules. The executives and management would go on and on about how they care about employees but do nothing to show it... and then management gets upset when you leave because you wanted opportunities to grow, as if you'd been disloyal and should've just been content to stick around. I enjoyed working at Datadog, but was often shocked at how much the executives micromanaged issues that they should have trusted others to manage and how petty the executives sometimes seemed to be. On top of all that, it's a company run by men and generally for men. There are no female executives or board members. The company pays lip service to seeking diversity (gender and otherwise), but it's not felt and I often found myself having to fight for people to recognize issues, let alone try to correct them.