Senior SDET - how to become software developer at FAANG and be AI relevant?

You're experiencing a very common problem. There are so many technologies, tools, and frameworks to learn as a Software Engineer. For someone who's trying to make a transition into a new field within engineering (SDET --> SWE), it's extremely difficult to decide where to invest. You don't want to spend a bunch of time learning something that ends up not being in demand.

My advice is to quiet the chatter of self-doubt and second-guessing. Don't spend too long trying to decide what to work on. Commit to something for a few months based on what you want to build or what your friends are familiar with. You can always change course later, but the learning starts only when you commit.

A related tactical piece of advice is that you should be polarizing. You want a hiring manager or recruiter to look at your resume/LinkedIn and have one of two reactions:

• This person is clearly not a good fit ("we use Python, they don't talk about Python at all")
• This person is a great fit ("I don't see many developers who know Rust so deeply, we should definitely interview them")

What you don't want is to be in the maybe bucket, where you've watered down your resume so much that you've mentioned all the buzzwords and technologies, but you appeal to no one in particular. As you become more and more Senior, you should aim to be increasingly polarizing.