One late task stalls forty downstream jobs every morning. Design a scheduler that owns dependencies, SLAs, and backfills.

Cron fires at wall-clock times; a scheduler reasons about data intervals and blocked frontiers. The scored details are per-partition idempotency and catch-up semantics.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.