IoT telemetry ingestion
Design an ingestion pipeline for 50 million IoT devices (smart meters, EV chargers, sensors) each emitting a small telemetry record every 10 seconds — ~5M writes/sec at peak, bursty when a firmware rollout reboots a region simultaneously. Records must be durably stored, queryable as time series, and trigger near-real-time alerts (e.g., over-temperature). Devices have weak/intermittent connectivity and limited buffering. How do you handle the massive fan-in without dropping data or melting the backend?
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.