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Coding Interview Questions

Coding interviews at quant and HFT shops test the same data-structures-and-algorithms core as any SWE loop, but with a twist: they prize clean reasoning about complexity, numerical stability, and streaming/online computation, and they love dressing problems in market clothing (order books, VWAP, dra

111 Problems 13 Easy 68 Medium 30 Hard
A curated set of 111 coding problems drawn from our bank — the kind that actually shows up in quant interviews, rewritten for clarity with worked solutions we author ourselves. We never claim a wording is verbatim. 9 are free to open and fully solve.

How to think about coding questions

The coding problems here aren't about syntax — they're about choosing the right structure before you type. Nearly every one comes down to spotting the pattern (search, recurrence, greedy choice) that turns an exponential brute force into something that runs.

REMEMBER, DON'T RECOMPUTE

When a problem's pieces overlap, dynamic programming caches subproblem answers so each is solved once — the difference between an exponential recursion and a polynomial table. The whole craft is naming the right state and the transition between states.

PICK THE RIGHT TOOL

Sorting, hashing, two pointers, a heap, binary search on the answer — each collapses a class of problems from O(n²) to O(n log n) or better. Recognizing which invariant the problem hands you (monotonicity, a bound, a structure) is what selects the tool.

The recurring move: before coding, find the structure — the overlapping subproblem, the monotone invariant — that makes the obvious brute force unnecessary.

Coding questions (111)

Coding interview questions FAQ

What kind of coding questions show up in quant interviews?

This page collects 111 coding problems that recur in quant trading and research interviews, each with a full worked solution and the intuition behind it. They range from quick warmups to the harder variants firms use to separate candidates.

How hard are coding interview questions?

The set spans 13 easy, 68 medium and 30 hard problems. Most sit at medium difficulty — a few minutes of clean reasoning — with a harder tail that rewards knowing the canonical approach rather than grinding.

How should I practice coding for quant interviews?

Work through them by difficulty, starting just below your level, and write the solution out before checking. 9 are free to open with the full worked solution, so you can judge the quality first. Focus on the recurring patterns rather than memorizing answers — the same handful of ideas generate most variants.

Are these real quant interview questions?

They are a curated set drawn from our problem bank — the kind of coding question that actually appears in quant interviews, rewritten for clarity with solutions we author ourselves. We don't claim any single wording is verbatim, and every problem carries a full solution.

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