I have more than 10 years of experience as a backend engineer. Does the top companies even hire folks like me for ML/AI positions? What are the interviews like? Anything different from regular software engineering interviews?
I imagine if you learn the requisite material, you could join these companies on a different team and later internal transfer to ML/AI
Nope. Not MSFT and not FB. At FB there’s a ML design round. But it’s doubtful recruiters will consider you unless you have experience (not necessarily formal education). So if you want to do this you need to get some experience (side projects, open source etc.)