Pros
Great culture & core values - Focus on Impact, Move Fast, Be Bold, Be Open - these are not just buzzwords but are the true embodiment of the company.
Great colleagues - The overwhelming majority of staff at FB are world-class at what they do and are dedicated to doing a great job.
Great working environment & perks. FB really takes care of their employees in pretty much every sense of the word.
The company innovates and iterates really quickly and, despite the speed, moves to a surprisingly high quality bar.
Cons
Not a real "con" per-se, but it would be great to have a broader set of engineering teams in Dublin.