[Mc91]

> I'm pretty confident that there are very few engineers at FAANG that can't be replaced. I'd also expect there are very few engineers at Epic, Activision, Blizzard, Naughty Dog, Sony, Rockstar, Ubisoft, Valve, etc... that can't be replaced. Sure, if 30%-70% of the team left on any particular project it would probably die

The thing is these two things are linked - one engineer leaving and 30-70% of a team leaving. The quantity of who leaves does not matter as much - a project may be able to handle 70% of consultants, interns, junior and regular programmers leaving, but might die if the 30% (or 25%, or 20%) leaving is entirely senior/staff/principal.

One of the lead programmers who has been at the company for many years leaves. He is friendly with some of the other senior programmers and says he thinks the company is slowly going downhill, and he got a new job with better money, and with a saner schedule, work environment and work-life balance. Maybe one of the other senior people leaves for the company he left for. Then other senior people start leaving.

It's like Steve Blank's essay about how a company deciding to start charging fifty cents for soda led to an exodus of its best senior programmers. One lead leaving can be a catalyst for others leaving. So they are in a sense irreplaceable.

If a company is an oligopoly like Verizon/AT&T or the like, then they are privy to revenue and profits they don't have to compete for, and for companies in that situation people are more replaceable. Not for companies that have to be competitive though.