Recruiters often mention that a staff engineer interview involves a deeper dive compared to a senior software engineer interview, but it's not clear how much deeper it needs to go. Are there any resources that can clarify this?
It's hard to quantify and really fuzzy, but I tried my best here: "What is the difference between a Senior and Staff engineer in a System Design Interview?"
I think the main way to understand it is to know the delta between a senior and staff engineer overall. I recommend going through the L5 -> L6 course if you really want to get it: [Course] Grow From Senior To Staff Engineer: L5 To L6
In short, I'd say the Staff Engineer should atriculate more opinions in a System Design interview compared to a Senior Engineer. These should be evidence-backed judgment calls that are based on past experience or forecasting various problems.
I'd highly recommend going through this course: The Top Ways People Fail System Design Interviews