How to prepare for a data analyst interview in one day
One day is enough to review, not to learn. Spend it on the SQL you will actually write, on one case said out loud and on your own stories — about four and a half hours of work, then rest.
Morning — the SQL you will actually write
about 2 hours
- Start with the warm-up in the SQL track: short problems with hints, so your hands remember the syntax.
- Then one problem on each pattern interviews love: second-highest value in a group (window functions), day-1 retention and a revenue query to fix (a JOIN that multiplies rows).
- Before each query, say what one row of the result means. That habit catches most mistakes.
Afternoon — metrics and one case
about 1.5 hours
- Open the cheat sheet for every metric the posting names: the formula, what moves it, what breaks it.
- Take one case without an interviewer: write a five-line plan — what to measure, which cuts, which checks, what you would decide — then compare it with the strong candidate’s walkthrough.
- For an A/B test, say out loud: the primary metric, two guardrail metrics (the ones that must not get worse), how long it runs and what you do if there is no difference.
Evening — your stories and your questions
about 1 hour
- Pick three stories: a project with a number at the end, a disagreement, a mistake you caught in time. Tell each in two minutes.
- Write three questions about the team’s metrics and data.
- Check the time zone, the link and who is interviewing. Then stop: a rested head beats one more problem.
Only two hours? Keep the SQL warm-up, one case and the three stories.
By the evening you can say yes to
Not checked? Leave it. In one day you fix what is close, not what is new.
Paste your posting
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