I’ve got coworkers who went back and forth. Their thoughts were (in 2019) that Facebook had cooler things going on, but less mature. Nicer to use, but less stable in some cases.

I personally loved things breaking at times. The monorepo and all the tools were so open that enabled me to follow along and try my own fixes in some cases (sometimes being the one to fix it!).

At that point in my career, that kind of exposure was like a rocket ship for personal growth. Others shared similar sentiments.