What differentiates a Senior vs Staff engineers in terms of :
I highly recommend going through this thread if you haven't already: "Quality to demonstrate for staff MLE during interview?"
A couple important caveats:
When it comes to differences, here's a couple that I've seen:
Again, these are more for product engineers, not those who are more on the infra side. Infra is more technically complex, so there's far more scope staying in the technical weeds as opposed to product which is generally regarded to run out of technical scope as you approach L6/Staff.
As a side note, I have generally found that as you get more and more senior, what you do on the job starts converging towards what the interview process looks like, primarily through the behavioral and system design angles. Hiring an L5 or L6 (senior/staff engineer) who can't actually hack it is so, so painful for everyone involved, so interviewers spent a lot of time and mental energy making sure that candidates have genuinely operated at these levels.
This is opposed to L3 and L4 (junior and mid-level) where you go through DSA gauntlets (especially for Big Tech) and you have to fake knowing system design (most L4s don't do system design on the job).
This is why I think it's very valuable, even for folks interviewing, to go through our senior -> staff playlist: [Taro Top 10] Senior Engineer To Staff Engineer (L5 To L6)