How do you monitor categorical features for drift?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
Track frequency of each level, the share of unknown or new levels, and entropy of the distribution.
WHY — Data Drift instead of guessing?
Why interviewers care about Data Drift:
question about Data Drift.
trade-offs, and what you would actually do on a MLOps project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Track frequency of each
level, the share of unknown or new levels, and entropy of the distribution.
- 2A flood of a
new device_os value is a classic silent break.
- 3Map unseen categories to
an explicit other bucket in both train and serve.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Track frequency of each level, the share of unknown or new levels, and entropy of the distribution. A flood of a new device_os value is a classic silent break.