I’m Michael. I was a principal engineer at Facebook from 2009 to 2017, where I was the top code contributor of all time and also conducted hundreds of interviews. I recently co-founded Formation.dev, an engineering fellowship that trains and refers engineers directly into big tech. Ask me Anything!

I can speak to my experience while I was there, but obviously not since I left, since that's all second hand. Day-to-day was extremely engineer driven. You had a lot of autonomy to work on what you wanted. The counter balance to that is that the performance review process is really intense and that's when the "impact" of your word is measured, debated, and compared to others at your level. What "impact" means is hard to define here, but at lower levels there are a lot of examples and the process is about collecting proper evidence via peer feedback to quantify your impact. Executive would review day-to-day and week-to-week work in live meetings with the team leads and give feedback and comments, but rarely top down commands at this level. That said, the high level decisions were entirely made by the executive team on a less frequent basis, such as quarterly goals. Engineers had less insight and involvement in setting those goals. Mark Zuckerberg, and the other leaders would be working on them.