The 60-second answer
Clarify the target—ETA, congestion, incidents, or route cost—and define horizon, freshness, geography, and downstream decision impact. Build event-time ingestion with map matching, deduplication, late-data handling, road topology, recent speeds, historical seasonality, weather/events, and neighboring-segment context.
Build the answer in this order
Clarify the target—ETA, congestion, incidents, or route cost—and define horizon, freshness, geography, and downstream decision impact.
Build event-time ingestion with map matching, deduplication, late-data handling, road topology, recent speeds, historical seasonality, weather/events, and neighboring-segment context.
Start with a strong baseline and add sequence/graph models only when time/geography backtests show meaningful gain.
Serve fresh features with historical fallbacks and monitor regional drift, sensor coverage, calibration, latency, and routing impact.
A useful interview mental model
This is the shape of a strong answer—not a script to memorize.
Senior-level signal
- Senior answers address graph dependencies, delayed/biased observations, regional cold start, and online/offline feature parity.
- Discuss how prediction uncertainty should change routing or fallback behavior.
What the interviewer is really testing
Likely follow-up questions
Common weak-answer patterns
- Jumping to a model before defining the product contract.
- Listing components without bottlenecks, metrics, or failure handling.
- Ignoring data quality, serving latency, monitoring, and iteration.