I'm going to join Meta as a new grad SWE in early June. I would be TNTE (too new to evaluate = automatic meets all) for the July PSC.
However, I would be evaluated in January's full-year PSC. How exactly would this work? I would have ~6mo of work done by Jan. Would I be pitted against other E3s in my org who have been working since Jan 2025? Or would they also consider my tenure at the company?
They will consider your tenure at the company. Key is for you to align quickly with your manager, once you’re in the seat, on what deliverables and outcomes will be for your first n months there before the review. Then work to own those outcomes and make noise when those outcomes are at risk.
Your tenure will be sort of "pro-rated", so you aren't just put on a PIP. However, this isn't that relevant for E3s anyways as they are held responsible for engineering excellence, not impact. I break this down in-depth here: https://www.jointaro.com/course/nail-your-promotion-as-a-software-engineer/impact/
The main thing to succeed as an E3 is coding velocity + quality. Follow the advice from the code quality course and you should be okay: Level Up Your Code Quality As A Software Engineer
All people will be evaluated only for the 6 months (the second half)