I think you may be selling yourself a little short.
Many, though perhaps not all, FAANG interviews do not involve needing to know THAT much CS trivia. The common topics (for many interviews, it depends on the company, and at non-homogenized companies, on the team) are:
- What’s a graph? What are some interesting strategies for walking a graph? Any gotchas to look out for?
- What is algorithmic complexity? How do you measure it? Why does it matter?
- Are you conversant with middle-school level arithmetic and geometry?
- Can you describe the strengths and weaknesses of the 4-5 most common simple data structures?
- Can you listen to problems as they’re described, and ask good clarifying questions (the most common problem is here, people didn’t bother to take the time to ask clarifying questions)?
- Once you’ve nailed down the problem, can you structure a few nested for-loops with relevant tests and perhaps a few simple auxiliary data structures?
- Once you have a potential solution, do you test your work? Do you skip over your mistakes pretending they don’t exist? Do you take hints when your mistakes are pointed out to you?
- Do you admit when you don’t know, then try exploring anyway?
Seriously, this is the entirety of what I see most FAANG interviews covering. If you’re a competent self taught programmer, you need to study a tiny bit about data structures and algorithms, stay calm, ask lots of questions, and just execute.
I get that there are lots of horror stories out there, and I genuinely feel for people who get super anxious when asked to work with an audience.
But if anxiety isn’t your problem, I encourage people to try different teams/companies if they’ve mastered what I’ve listed. FAANG really don’t want to put the bar absurdly high, they want a relatively easy level of CS knowledge.