I worked at a startup with ~7/8 friends and made many more while I was there. One or two of them definitely made me question my worth as an engineer while worki

I worked at a startup with ~7/8 friends and made many more while I was there. One or two of them definitely made me question my worth as an engineer while working there (read: poor management skills (edit: awful management skills, they were eventually moved out of managing)), but I don't think it ever affected our friendship outside of work. In the end there was a big restructure post investment round and a lot of people who had been there for a long time felt it was right to move on (or were heavily suggested to move on, or pushed out). I left a few months after that on very good terms to keep the good memories good, and joined another friend at another startup which I really enjoyed. My mentality during that time was: Do your best work, learn as much as you can and be agreeable - you might be friends, but there is still hierarchy in the business which you should respect. Outside of work, you be you. It worked well for me. YMMV.