How much of ML experience is needed/looked at during Team Match, if particulary interested in joining a team doing ML? Are Hiring Managers particular about this requirement during TM? This is for a E5 and E4 levels.
Given that you're currently staff, I imagine you wouldn't be allowed to join as an E4. For E5 MLE, the bar will be pretty high. In terms of # of years, I would say minimum 4, but it really depends on quality of experience. For example, 3 years at Google as an MLE is probably worth 5+ years of ML experience at most other companies. Meta is well aware of company quality, so they will be applying this internal multiplier.
Are you an MLE right now? If not, I recommend getting into Meta under whatever tech stack you do, establishing yourself as a high-performer (will take 1 year minimum), and then requesting a switch. I've seen several Meta E5s from non-ML backgrounds pivot into MLE this way. More thoughts here: "Is it worth transitioning to become a Machine Learning Engineer?"
I left some thoughts about the Meta team matching strategy here: How to navigate through team matching with Meta?
The amount of ML experience needed will depend on the team -- I'd say that most hiring managers (HMs) will be quite particular since there are so many amazing engineers to pick from.
(Since bootcamp is no longer used for team matching, my advice is to pick the first team where you have a match. Internal mobility is pretty good at Meta.)