The other thing I do is ask questions about disagreements with previous coworkers or managers

I like these kinds of questions as well, but I keep it to technical disagreements (i.e. best idea wins) since we have another round where we cover soft skills specifically.

map out a loose architecture for some sort of API data process or frontend data process

I think this is pretty easy to BS through though.

We usually cover this as a follow up to a live coding exercise, where we ask them, without any code, how they’d adjust the project if the requirements change. How can they optimize for storage size? Lookup performance? As it gets more complex, what can we do to keep it maintainable? If we add feature X, is it better to put that on the FE or BE? Why?