Finance Track

Quant Interview Prep

Three different jobs share one label, and firms interview them differently. Trading is decisions under time pressure, research is statistical judgement, development is systems. Preparing for the wrong one is the most common way strong candidates fail.

1,000+ candidates coached into top-tier firms

What We Cover

Mental arithmetic at speed, and why firms test it when nobody does long division on a desk
Probability: conditional, Bayes, and the classic urn and coin problems that keep reappearing
Expected value and variance, and pricing a bet you are offered rather than one you chose
Market-making games: quoting a two-way price, managing the position you get filled on
Combinatorics and counting arguments, where most candidates lose time rather than accuracy
Brainteasers as a proxy for structured thinking, and how to narrate one badly or well
Statistics for quant research: regression, stationarity, overfitting, and what a backtest cannot tell you
Programming for quant dev: data structures, complexity, and low-latency thinking
The three role families and how to tell from a job description which one you are being tested for

Common Quant Interview Questions

1

You flip a fair coin until you see two heads in a row. What is the expected number of flips?

2

I roll a die. You may accept the value or re-roll, up to three times. What is the game worth?

3

Make me a market on the number of petrol stations in the country.

4

What is 17 x 43? Now do it again with 18 x 42 and tell me why the second is easier.

5

A test is 99% accurate for a disease that affects 1 in 10,000. You test positive. What now?

6

Two players alternate removing 1-3 coins from a pile of 21. Who wins with perfect play?

7

You have a strategy with a Sharpe of 2 in backtest. What would make you not trade it?

8

Why quant trading rather than research, or the other way round?

9

You are quoting a market and get filled on your entire bid immediately. What do you infer?

These are real questions asked in quant interviews. Our coaching covers how to structure and deliver winning answers.

What Top Firms Look For

Speed with accuracy, in that order of surprise: most candidates are accurate and slow, and firms already know slow is trainable less often than they would like

Thinking out loud in a way someone can follow and interrupt, because that is the actual job on a desk

Being wrong well — updating fast, without either defending the first answer or abandoning it at the first push

Genuine curiosity about markets rather than a rehearsed reason for wanting the seat

Comfort with an incomplete question, since a badly specified problem is the normal case

A Day in the Life: Quant

A trading seat starts before the open with overnight moves and position checks, then runs on decisions measured in seconds and reviewed in aggregate. Research looks nothing like it: longer horizons, most of the day in data and code, and the output is a signal or a paper rather than a fill. Development sits alongside both, owning the systems that make either possible. What the three share is a scoreboard — the work is measured more directly than almost anywhere else in finance, which is the appeal and the pressure in equal measure.

How to Break Into Quant

1

Work out which of the three families you are actually applying to before you prepare for any of them

2

Drill mental arithmetic to the point of boredom; it is the cheapest edge and the most commonly under-prepared

3

Do probability problems out loud, to another person, because the narration is half of what is assessed

4

Build one thing end to end — a backtest, a simulator, a market-making bot — and be ready to explain what it does badly

5

Apply early: quant timelines run ahead of banking, and the strongest firms close before many candidates have started

6

Do not neglect the "why us" answer. Technical strength does not excuse having no view on the firm you are sitting in

Guides for this track

The written material behind the coaching, free to read.

Frequently Asked Questions

Do I need a PhD for quant roles?

For quant research at many funds, usually yes or close to it. For quant trading, frequently not — several of the largest trading firms hire undergraduates directly and train them, and value speed and decision quality over depth of publication. Quant development sits closer to a strong software engineering bar. Reading the requirements for the specific family you want is more useful than a general answer.

How much does the mental arithmetic actually matter?

More than candidates expect, and not for the reason they assume. Nobody needs mental arithmetic on a modern desk. It is used as a cheap, hard-to-fake proxy for working under time pressure without becoming careless, and it is one of the few parts of the process you can improve reliably with practice.

What is the difference between quant trading and quant research?

Trading is decision-making under time pressure with an immediate scoreboard. Research is statistical work over longer horizons where the output is a signal, and the feedback loop is measured in weeks rather than seconds. The interviews reflect that: trading leans on games, speed and market-making; research leans on statistics, and on whether you know why a backtest lies to you.

When does quant recruiting happen?

Earlier than banking, and it moves. Several firms open summer applications in the spring or summer of the preceding year and close them once full, so a candidate working to a banking timeline can find the process finished before they start. Check each firm directly rather than assuming a cycle.

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Your Coach: Surojit Chakraverti

Citigroup · Rothschild & Co · Hedge Fund CIO

Surojit is a hedge fund CIO (Third Wave Capital, previously Redline) and former investment banker who worked at Citigroup and Rothschild — with his core deal experience in M&A at Citi and Rothschild. He has personally coached over 1,000 candidates into roles at Goldman Sachs, Blackstone, KKR, Google, McKinsey, and dozens of other top-tier firms.

Every quant coaching session is tailored to your specific targets, timeline, and experience level. No generic advice, just the insider knowledge that separates offers from rejections.

Ready to Ace Your Quant Interview?

Get 1:1 coaching from professionals who have been through the process and sat on the other side of the table. No generic advice, just what actually works.

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Coached by Surojit Chakraverti — Citi, Rothschild, Third Wave Capital