Pros
People are awesome and friendly. Always lots of cake on birthdays, team lunches (in the nice casual way, not boring mandatory kind) The work we get to do is fulfilling and exciting. Good opportunities for travel. Is run like a social enterprise more than a non-profit, keeps things sustainable, and people working hard. You always feel like colleagues are working as hard as you are. Pay and benefits are good for a non-profit, but not on par with private, but if money is what drives you then it's probably not a good fit anyway.
Cons
The team is distributed across the world. half in D.C and the rest in Argnetina, Romania, and a couple scattered around. It makes travelling fun and exciting, but means a lot of tele-working and communicating instead of in person which takes some getting used to.