Quant Interview Diagnostic Test
How to run a quant interview diagnostic test and turn the result into a focused prep plan.
Candidates who are unsure which quant interview topics need the most work.
What a diagnostic should measure
A useful diagnostic measures methods, not confidence. Include probability setup, counting, conditional probability, expected value, mental math, estimation, statistics intuition, and communication. The result should tell you what to practice next, not just produce a score.
Build a mixed set
Use a small mixed set before you specialize. Ten to fifteen questions is enough to expose obvious gaps if the set spans methods. Include at least one problem where order matters, one conditioning problem, one expected value question, one mental math task, and one explanation-heavy prompt.
Score misses by cause
For each miss, tag the cause: setup, method choice, arithmetic, time pressure, communication, or review discipline. A wrong answer from bad arithmetic needs a different fix than a wrong answer from choosing the wrong sample space.
Concrete example
If you miss a dice maximum problem, a Bayes base-rate problem, and a card hand problem, the surface topics differ. The shared cause might be denominator discipline. That points to focused probability setup practice before more mixed sets.
Turn results into the next week
Pick the top two causes and schedule repair blocks. If conditioning is weak, use Bayes, cards, and conditional probability. If communication is weak, redo solved problems aloud. Retest after the repair block rather than assuming the issue is fixed.
Common mistakes
Candidates often make diagnostics too long, too narrow, or too easy. Another mistake is ignoring the result because it conflicts with the plan they wanted to follow. Let the diagnostic choose the next block.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.