Your question is Token Generation System. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Design an algorithm for generating limited tokens: x tokens become available every y hours, expire in z hours if unused, max daily limit c, one active token per person, time-boxed service slots, paid tokens to skip the line
This was asked as a practical interview question. Explain the data model, allocation algorithm, concurrency control, expiry handling, and how you would test edge cases.