Seems like it's always the best time to be here
Pros
Everything in engineering is cutting edge. The projects we get to take on are huge, and there's lots of learning to be done. The decisions for engineering are made by me, not handed down by someone else. The culture is also made by me, not handed down by someone else. (As an individual, you own the experience/culture/projects at FB just as much as anyone else does) Currently, I have an awesome manager who is helping me to personally grow as well. Also, it seems like all of the cultural decisions that were made by the m-team here are extremely well thought out. They always seem to be the most natural / reasonable decisions
Cons
None yet. My work life balance on my own was never that consistent. I would work really hard some days, and not do much the other days. I still follow that pattern.