EDFMediumMachine Learning00:00

Welcome to your interview for the Research Scientist role at EDF.
The question is on your right: Predict Turbine Failures from Sensor Data. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen. You have three graded attempts to score 7/10 or better.
AeroGrid operates 1,200 industrial gas turbines across power plants in North America. Unplanned turbine downtime is expensive, so the reliability team wants a model that predicts whether a turbine will require a maintenance intervention within the next 7 days, using historical sensor and maintenance data.
The training data is built at the turbine-day level from SCADA logs, alarm events, and maintenance records.
| Feature Group | Count | Examples |
|---|---|---|
| Sensor aggregates | 28 | avg_bearing_temp_1h, max_vibration_24h, exhaust_temp_std_6h, oil_pressure_min_12h |
| Operating context | 9 | ambient_temp, load_pct, startup_count_7d, runtime_hours_since_overhaul |
| Alarm/event features | 7 | alarm_count_24h, critical_alarm_flag, trip_events_30d |
| Asset metadata | 6 | turbine_model, site_id, fuel_type, turbine_age_years |
| Maintenance history | 5 | days_since_last_service, prior_failure_count_180d, replaced_component_type |
A production-ready model should achieve strong early-warning performance: PR-AUC above 0.45, recall above 75% at precision of at least 35%, and top-decile lift above 4x versus random ranking.