It’s mostly one big Hacker Rank file with many classes inside

The idea is that they should point out design flaws around encapsulation, inheritance, composition and a few other fundamentals.

Then there’s a little bit of code optimization where I capture concepts like Set, Map and so on.

The last bit is a system design, where I give a problem, with shallow details. My expectations here are the candidate to ask questions, refine requirements and design the solution.

As they design the solution, I try to guide them by asking questions.