Practice

Short problems that build real judgement

Every question has a worked solution that explains why the answer is right, not just what it is. Free, no account needed.

SQL

Joins, window functions, aggregation and the queries interviews actually ask for.

3 questions

Data manipulation, logic and the standard library patterns that keep recurring.

3 questions

DAX, modelling decisions and performance reasoning.

2 questions

Reading data honestly: distributions, comparisons and traps.

1 question

Modelling judgement, validation and evaluation.

1 question

RAG design, agent reliability, evaluation and cost control.

1 question

Requirements, stakeholders and turning a vague ask into a spec.

1 question

The Interview Lab covers the questions that actually get asked, with the reasoning an interviewer is listening for rather than just a model answer.