What is a KPI?
PICTURE THIS: DJANGO MVT
Simple meaning
A KPI is a key performance indicator: a metric the business uses to judge success at a chosen grain and window.
WHY — Business Metrics instead of guessing?
Why interviewers care about Business Metrics:
people who only read docs from people who shipped.
and tied to Data Science 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:
- 1A KPI is a
key performance indicator: a metric the business uses to judge success at a chosen grain and window.
- 2Good KPIs are measurable,
tied to strategy, and hard to game without real value.
- 3Interviews expect you to
define numerator, denominator, and time window, not just a slogan.
- 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
A KPI is a key performance indicator: a metric the business uses to judge success at a chosen grain and window. Good KPIs are measurable, tied to strategy, and hard to game without real value.