Interview concept
How it works
Resource isolation
Separate thread pools, connection pools, queues, or service instances prevent one caller or dependency from consuming the shared capacity.
Failure containment
An overloaded reporting job can fail within its partition while checkout or another critical path continues serving requests.
Sizing tradeoff
Too little isolation allows noisy-neighbor failures, while too much strands spare capacity in a pool that other work cannot borrow.
Priority boundaries
Bulkheads work well when traffic classes have different importance, latency goals, or failure characteristics.