Quant Interview Prep Roadmap
A practical roadmap for quant interview prep: diagnose your level, sequence core topics, practice deliberately, and know when you are ready for mocks.
Candidates starting quant interview prep who need a clear sequence instead of a pile of random questions.
Start with a baseline
A roadmap only works if it starts from measured level rather than ambition. Run a mixed diagnostic of twelve to fifteen questions spanning sample-space setup, counting, conditional probability, expected value, mental arithmetic, estimation, and one explain-out-loud prompt, at roughly three minutes per question. Then tag each miss by method rather than by surface topic, because a card question is usually a combinations question and a trading game is usually an expected value question in costume. Three misses that all trace back to a wrong denominator are one problem, not three, and they get one repair block, not three.
Sequence the core topics
Sequence by dependency, not by interest. Sample-space discipline and counting come first, because conditional probability, Bayes, and expected value all inherit their denominators from them. Linearity of expectation and indicator variables come next, since they collapse problems that would otherwise need enumeration. State recursion and first-step analysis follow, because stopping problems and random walks are just recurrences on a small state. Market making arrives last, once arithmetic is reliable enough that computing a midpoint does not consume the whole interview. Statistics intuition and estimation can run in parallel with any of these - they do not depend on the earlier layers.
Use a weekly practice loop
A productive week has one mixed or diagnostic block, two focused repair blocks, one timed block, and one review session - five sessions of roughly sixty minutes. The repair blocks are chosen by the error log, not by the calendar: if the diagnostic shows weak conditioning, spend both on Bayes tables, cards without replacement, and first-step analysis before returning to mixed probability. The measure of a good week is not problems attempted but whether one named miss stopped recurring. Ten reviewed problems that kill a conditioning error are worth more than fifty familiar prompts.
Concrete roadmap example
A six-week plan for a candidate with about five hours a week: week one is the diagnostic plus sample spaces, complements, and counting; week two is conditional probability, Bayes tables, and combinatorics, closing with a retest of the week-one misses; week three is expected value - linearity, indicator variables, and one-step stopping games; week four is statistics intuition and mental arithmetic, with ten minutes of daily fraction and percentage work; week five is market making and trading games plus two timed mixed sets; week six is two or three mocks and repair of whatever they expose. The order shifts with your diagnostic, but the loop does not: diagnose, repair, mix, retest.
Common mistakes
The most common failure is collecting resources instead of practicing - a bookmarked reading list feels like progress and produces none. Close behind: memorizing famous puzzles, which interviewers defeat by varying the setup; moving to timed mocks before the methods are reliable, which trains speed on a broken model; and treating a solved problem as evidence of readiness because it looked familiar. Readiness means solving variants, stating assumptions unprompted, and recovering when the interviewer changes the rules mid-problem.
Prep path
Use the LeetQuidity calibration to find the weakest bucket, then work the matching curriculum chapter or guide topic before returning to mixed practice. Start mocks once misses are rare and each one is explainable. If a mock exposes the same failure mode twice, stop broad practice and repair that method directly - broad practice will not surface it again for weeks, and the interview will.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.