Part of the interview for my last job involved interviewing me about debugging, which I thought was neat. "What's wrong with this code?" All the samples were relatively simple - less than 30 lines each?

- Double delete, caused by not following the rule of 3 in C++, which would likely crash - Multithreading code missing volatile or memory barriers (which segued into a discussion of it's disassembly) - Nonvirtual delete through base pointer

Extremely realistic - it's all stuff I've seen and fixed in the wild (this was for a non-entry gamedev job involving plenty of C++)

For people with 5+ years of experience (like OP), I look at and talk about their portfolio; he did actually built stuff that runs in production, so let's see how that came to be. And show parts you have written and are proud of. We are probably in that interview because your skill set matches (somewhat) the problems we are trying to solve, hence your past projects will have similarities with our projects. That interests me. I can find out if you are a self starter, if you have any business sense by chance, management/tutor potential etc. That you can solve some complex thing in 5 minutes is of no interest to me at all, ever.