What is data drift?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
Data drift is a change in the distribution of model inputs compared with the data the model was trained on.
WHY — Data Drift instead of guessing?
Why interviewers care about Data Drift:
people who only read docs from people who shipped.
and tied to MLOps work.
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:
- 1Data drift is a
change in the distribution of model inputs compared with the data the model was trained on.
- 2Traffic mix, seasonality, or
a new product line can all shift features.
- 3If you do not
detect it, accuracy can fall while the service still looks healthy.
- 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
Data drift is a change in the distribution of model inputs compared with the data the model was trained on. Traffic mix, seasonality, or a new product line can all shift features.