You have 35 minutes to design a document export service for fictional Alder Research.
The assessment follows a common job interview sequence: requirements, estimates, API, model, architecture and a failure discussion. These are original tasks with checked deliverables, not questions from an employer assessment.
Exports may run for several minutes, so an accepted request needs a durable identity and a status clients can revisit. A worker can crash after it creates the file but before acknowledging the job. Your design must return the existing result on retry, keep private files behind authorization and avoid holding a request open while a full export runs. Each step carries the same design forward. Use the clock to reserve time for the failure boundary, rather than spending the whole interview on component names.