Depends what you mean by brain drain I suppose. People will leave. Tech workers are not very loyal anyway though so some churn is inevitable. Amazon has enough

Depends what you mean by brain drain I suppose. People will leave. Tech workers are not very loyal anyway though so some churn is inevitable. Amazon has enough prestige that they'll be able to recruit smart engineers to replace those leaving. I think the important question here would be if there is knowledge loss which can't easily be replaced. I'm sure there will be some, but will it be significant? Probably not. I've seen engineering teams cut in half without significant knowledge loss. By significant I mean engineers are confused about how significant parts of the system work because the team that maintained those parts of the system are no longer around. Generally what happens is you lose people with familiarity with certain parts of the system so productivity drops temporarily, but broadly the team still understands how all the bits fit to together.