Scheduled jobs platform
Design a scheduled-jobs / cron platform that lets ~10K internal services register recurring jobs (cron expressions) and one-off delayed tasks. Scale: ~2M scheduled executions/day, jobs range from 100ms to 30min, some are critical (billing runs) and must fire exactly on time. Requirements: a job must fire even if a scheduler node crashes, must NOT fire twice (or must be idempotent), late jobs (missed window during an outage) need a defined catch-up policy, and the system must scale horizontally without two schedulers double-firing the same job.
What a strong answer looks like
Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts (data model, bottlenecks, consistency, failure modes) and name the trade-offs you are making.
Clarify5:00 left
Estimate5:00 planned
Design15:00 planned
Deep dive12:00 planned
Failure8:00 planned
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.