Generalist to Staff role

My question has originated from the courses by you and Rahul, and the general idea I got is I need to be the best in one domain and tech stack (Practice that one kick 1000 times, instead of 1000 kicks one time). From my background and tech switches I feel like I have lost that. How do I salvage my career now, if I want to get back on track? How many years do you think and what kind/area of effort should I put in? By switching to ML, did I move back to the fresher stage?
Unrelated: Is senior a terminal level at Meta, or is there an expectation to move to staff within x years?

Becoming a Staff Engineer requires an incredible amount of technical depth, so yes, switching to ML will definitely set you back several years at least with this promotion. Stuff like this is why I generally recommend against pivoting into the "flavor-of-the-month" tech stack as the cost is quite high.

I actually think most engineers come out net-negative with these pivots as yes, they're switching into the hotter domain, but they're losing all that domain expertise from before, which is awful for promotion and being a high-performer in general.

By switching to ML, did I move back to the fresher stage?

Definitely not as senior engineers like yourself generally have a lot of fundamental skills like communication, mentorship, and project management (you know, all the stuff we talk about in Taro) that allow you to add value regardless of tech stack. So hopefully it just moved you to the earlier-end of the senior spectrum, upper-end mid-level at worst.

Unrelated: Is senior a terminal level at Meta, or is there an expectation to move to staff within x years?

E5 is terminal. There is 0 expectation to move to E6. Being E6, especially in this economy, is extremely hard.

Thank you appreciate such quick responses and helpful guidelines and amazing courses. If you do have any tips to now move fast through the ML role (hoping to get promoted, not soon, but hopefully soon enough), please do share. Thanks again!!!

I'm not an ML engineer, so I'll delegate the technical advice to this discussion: "How to build depth as a machine learning engineer?"

Overall, I recommend being inquisitive (and humble!), adding value to others, and building relationships with talented ML people (and Staff+ engineers in general) so they'll teach you. In other words, following the advice from here: "What’s the most effective way to switch domains in tech?"