GPU Credit Ledger with Expiring Grants, Out-of-Order Operations and Fast Balances
Company: OpenAI
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: hard
Interview Round: Onsite
Overview: Implement a GPU credit ledger with expiring grants, subtractions that spend the soonest-expiring credits first, and balance queries, where operations can arrive out of timestamp order. Then avoid recomputing from time zero on every query. It tests event replay, priority queues and checkpoint invalidation.