Startup to Big Tech Senior Role: Feasibility and Strategy

I recently moved from a big tech company (SDE2) to a startup for a higher role, hoping it would position me better for senior roles at big tech later. But it seems there’s no clear 1:1 mapping between startup and big tech levels, and roles often get downleveled during hiring. How feasible is it to transition from a startup to a senior engineer role (SDE3/L5 at Google or E5 at Meta), especially with prior big tech experience (5 YOE as SDE2 at big tech and 1 YOE at a startup)? Also, what’s the best way to get interview calls for these roles. Also do referrals make any significant difference?

Thanks!