I learned about the company at the campus event and applied for the QR Intern position. The process is OA -> HR interview -> technical interview -> final interview.
OA mainly involves SHL assessment, including behavioral questions, graphic reasoning, etc. It is recommended to practice in advance if you haven't done similar assessments before.
HR interviews involve walkthrough resumes and behavioral issues to assess communication skills and team fit. No math questions.
The technical interview mainly involves math and programming questions.

It had two parts: 1. a personality quiz where you were constantly presented with 3 statements and you had to rank them in terms of what applied most to you. Second, there was an inductive reasoning quiz. A lot of complete the sequence (although not numerical sequences, think shapes & colors etc.)

After applying and passing resume screen (high marks, appropriate degree, some relevant projects or past internships), an OA is sent. OA is very standard, with Bayes and LOTP questions with some brainteasers and statistics questions.
Got back to me very quickly (1-2 days) after submitting OA, and organised a recruiter 1-1 via Calendly. Recruiter call was standard behavioural, with questions about why trading, why IMC and some stories about showing resilience, leadership and being competitive. They say they will get back to you about next steps at the start of the next week, which they honoured.
Got an email for a technical interview, which is 2 back-to-back 1-on-1 interviews with traders asking open ended questions. While I can't share specifics, no preparation is really needed (aside from some game theory ideas) as questions mainly assess how you make bets / decisions and how you justify them / react to being wrong. There is no pressure to be quick - you can write everything down and take your time. Both interviewers weren't particularly happy to be there, but they were nice and happy to answer questions and didn't put any pressure to answer quick or anything.
The next day, a recruiter called to schedule a final round, which requries >0.5 business days at the office. If you are not based in the city, they will provide transport and hotel. The final superday consists of lunch, trading-desk shadow (more of a Q&A with a trader on the floor), 2 technicals and 1 behavioural. Behavioural is similar to first round, but they restrict topics you can talk about and ask follow-up questions. Some q's include "what would you do if trading doesn't work out", "what makes a good trader" and multiple stories of past failure and how you dealt with it. Technicals included a trading simulator and a more classic QT interview but very open ended. Both of these cannot be prepped for and you will make loads of mistakes, but they are testing how quickly you can recover from these mistakes and how you respond to feedback. Desk shadow they put a lot of emphasis on asking questions - try to ask questions specific about the intern process, as the trader you meet is an ex-intern. In this superday, everyone I met was exceptionally nice. Everyone was happy to chat about their roles and seemed very interested in getting to know me. The recruiters also look after you, giving you a tour of the office and providing you with snacks throughout the day and encouraging you. I think this is a better reflection of the office culture, as the traders from the previous round were probably tired of video calling so many interviewees.
Received a phone call the next week with an offer, with paper work following a few hours later.

Online assessment. Then behavioral with hr. Then a technical interview with one of the traders. Then an in-person super at the office.

First I had to do a games-based assesment. After that, I had a sort of "hirevue" with technical and behavioural questions. And then an interview with a recruiter, behavioral but also technical which I wasn't expecting.

Neurolympics assessment, HireVue with maths question, online interview with HR, Final Round Assessment Day

Started with a brain test (testing reaction speed, concentration etc). Once you passed, it moved to the HV stage. Three questions, 2 behavioural/motivation and 1 technical. Then it moved to the technical interview stage which was an online interview with a member on the recruitement team. It inolved basic probability and a mini trading game.

First round play Neurolympics (google it online it's very simple). Then do a hirevue which involves a maths question and from experience it only matters that you get the maths question right. This is followed by two more HR/technical interviews with fairly straightforward maths questions.

The interview process at IMC Trading (or similar firms) usually starts with some kind of online test. It’s mostly coding stuff, algorithms, a bit stressful because it’s timed, but not too crazy.

After that, if you pass, a recruiter calls you. They ask why you like trading, what you did before, nothing too deep. Just making sure you’re a real person and not a bot.

Then come the technical interviews. This is where they really start digging. They ask a lot of low-level C++ questions — things like memory, move constructors, CPU caches, why the compiler does X, what happens if two threads write next to each other (false sharing stuff). Sometimes they ask you to explain your projects and they really grill you on them.

Later, if things go well, there is usually a “final round” or a superday. Multiple interviews in one day, more C++, more performance questions, some system design but low-latency style (nothing like web apps). They want to see how you think under pressure.

At the end, they also check culture fit, teamwork, and if you’re curious, quick learner, etc. If all goes well, they send an offer. If not, usually they give no details, just a short rejection email.

The application process at IMC begins with submitting an online application through their official careers website. After that, the first step is an online assessment, which typically includes two LeetCode-style algorithmic problems of medium to hard difficulty. These are designed to test your problem-solving ability, data structures knowledge, and efficiency under time pressure.

If you pass the coding assessment, the next step is a one-way video interview, where you record answers to a few technical and reasoning questions. For example, one question could involve designing an in-memory hotel booking system, where you must discuss which data structures you would use and why.

Following that, there’s a 15-minute recruiter screen. In this call, you briefly go through your background, motivation, and interest in trading or software development at IMC.

The next stage is the first technical round, which lasts around 45 minutes. This interview is highly conceptual and focuses on C++ (or Java, depending on your track), memory management, OS fundamentals, and data structures. Topics can include:

Differences between lists, sets, maps, and unordered maps

How hash tables work and how collisions are handled

Stack vs heap memory, cache organization (L1/L2/L3), and cache efficiency

Smart pointers, references vs pointers

Hardware-level memory management and caching behavior

You’re expected to explain how things work under the hood (e.g., CPU cache prefetching, memory fragmentation, virtual memory, etc.) and sometimes reason about performance or memory trade-offs.

If you advance, the final round typically consists of two parts:

A technical interview focused on building or extending a simple matching engine (simulating order matching logic).

A behavioral interview and informal chat with team members or a hiring manager, discussing teamwork, motivation, and fit within IMC’s culture.

Advice:
It’s best to study C++ internals, OS concepts (memory hierarchy, caching, virtual memory), and data structure performance in depth. Be prepared to reason about what happens “under the hood” rather than just giving definitions. The overall interview atmosphere is challenging but friendly—interviewers value clear, structured reasoning and curiosity about how systems work at a low level.