Implement a precision-recall (or ROC) curve and AUC from scores and labels.
Building a PR/ROC curve from scratch shows you understand thresholds and the precision/recall tradeoff. What interviewers really want is sweeping the threshold in one sorted pass and integrating the area. The implementation follows.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Building a PR/ROC curve from scratch shows you understand thresholds and the precision/recall tradeoff. What interviewers really want is sweeping the threshold in one sorted pass and integrating the area. The implementation follows.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
