New hire -- How should I ramp up quickly and survive the first performance review ?

Congrats on getting into Meta! First thing's first - Take our onboarding course (it has senior-specific lessons too): The Complete Onboarding Guide For Software Engineers

It seems like Meta is your first FAANG-level company so senior expectations are probably higher than what you're used to for senior. For folks who are breaking into FAANG, I always highly recommend our promotion courses (even though you're not looking for a promotion right now) to get to their current level to thoroughly understand how FAANG engineers are evaluated. So for you, go through the L4 -> L5 course here: Grow From Mid-Level To Senior Engineer: L4 To L5

Among engineers I saw who were cut in their first PSC, they were largely E5 and above. This is because E5 is when expectations start getting really high, and most of them came from companies where senior was more like E4. I highly, highly recommend that L4 -> L5 course after going through the onboarding one, and after that, go through the full mid-level to senior learning path: https://www.jointaro.com/learning-paths/nail-your-promotion-mid-level-to-senior-l4-to-l5/

One of the specific tactics I recommend in the course is "Talk & Observe" -- basically shadow someone who is a high performer on your team and try to emulate their behavior when you're starting out.

If you are doing roughly what they are doing (at least in terms of inputs, hopefully outputs will follow), you will at least feel comfortable that you're not completely off base.

Do you have an onboarding buddy there or another engineer that's also L5 or above? I'd build a relationship with them and leverage them to get a high-level view of the system and all the tooling etc that powers your specific team's features.

It's totally fair to ask to set up time with them for an initial meet & greet + a get a high-level diagram of the entire system along with the plumbing tooling. At the end of the meeting, you can them if they'd be open to future meetings/questions, and you can use that to ask targeted questions later on.

In my repeated experience, this approach is much more efficient than trying to figure it out on your own (and building up anxiety over low output along the way).

I'd also take extra time in evenings and weekends to ramp up on these peripheral tools and systems to get up and running quickly. I am not a proponent of bad WLB, but sometimes it's just the need of the hour, esp. when performance at new job is at stake.