Multi-consumer CDC with schema evolution
Design a change-data-capture pipeline that streams every insert/update/delete from a fleet of production OLTP databases into a data lake and several downstream consumers, with no gaps and no double-counting. You must handle initial backfill of huge existing tables, then switch seamlessly to live tailing, survive DB failovers, and propagate schema changes (a column added/renamed) without breaking consumers. Scale: 500 tables, 1M row-changes/sec aggregate.
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.
Clarify5:30 left
Estimate5:30 planned
Design16:30 planned
Deep dive13:30 planned
Failure9:00 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.