I have been on a half a year long break due to unemployment and recently secured an offer at Meta as a senior. I'm a bit stressed about hitting the ground running after coming back from a hiatus, especially because I'll be joining as a senior and am coming as a mid level engineer from a non-faang company. I have a month long break still left before my joining date and I wonder if there is something I can do to set myself up for success.
Additionally how would I go about finding a mentor specifically who has had a good amount of experience working at Meta already?
I highly recommend going through [Masterclass] How To Succeed At A New Team Or Company As A Software Engineer.
I don't think you should stress too much before joining the company -- Meta has a great onboarding process, and anyway it's hard to know what to do when you don't have access to all the code/people/info that comes from being an employee.
If you really wanted to study, I would:
For finding a mentor:
I recommend becoming familiar with L5 expectations at Big Tech with this: [Taro Top 10] Mid-Level Engineer To Senior Engineer (L4 To L5)
Aside from that, I would relax as the rest will have better ROI for your mental state than furiously cramming before you start. You already grinded hard to pass the interview - Take a break! Meta in particular is a very hard company to prepare for as all the tech there is very custom, and its culture is very unique. It's best to just go in fresh and take it all in.
If you're going through bootcamp, you will have a bootcamp mentor. You can leverage them to familiarize yourself with the Meta way of doing things. After you join a team, you can look for an onboarding buddy/longer-term mentor.
Meta-point: I highly recommend starting more discussions in Taro after you start with whatever's top-of-mind for you, checking in every 2-3 weeks. I've onboarded a ton of engineers into Meta successfully, and I'm happy to continue doing so through Taro. But I can only do that if you continue sharing your situation as I can't read minds 😉