Meta

• Culture is generally very open; you can make suggestions or complain without feeling uncomfortable.
• Free food (breakfast, lunch, dinner & snacks), and amenities at the office (massage chairs, sleeping pods).

The codebase is hard to work with. Some parts have little documentation, and it's often necessary to ask people who have worked on relevant parts of the code to get an adequate understanding.

Facebook London pays (very) significantly lower than in the US and has fewer teams to choose from.

Engineering-wise, it would probably be better for long-term growth to give more priority to sustainability, especially of the codebase, particularly since FB is expanding so quickly.