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IMC interview notes, page 2 of 3

Large Enterprises

Most of these IMC write-ups come from Software Engineers (20), then Machine Learning Engineers (5) and Data Scientists (1). The most reported rounds are the technical phone screen (18), the online assessment (2), the system design round (2) and the recruiter screen (2).

26 interview notes · updated Jul 2026

IMC·Software Engineer·Onsite - Behavioral / Leadership

May 2026
IMC software engineer interview with a behavioral-style prompt asking you to explain a past project to a non-technical audience. Pretty straightforward in concept but harder to nail than it sounds.
  • Walk me through a project you worked on: what problem it solved, your role, what you built or changed, the outcome, and one challenge you faced. Explain it as if I have no technical background.

“This tripped me up more than I expected.”

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IMC·Machine Learning Engineer·Technical Phone Screen

May 2026
IMC ML Engineer interview that went into some surprisingly quant-heavy territory. The probability and linear algebra questions felt more like a quant finance screen than anything ML-specific, which I wasn't fully prepared for.
  • You have a probability model with three outcomes where the probabilities are defined as q, q squared, and 1 minus q minus q squared. What is the valid range of q such that all three values are legitimate probabilities?
  • Given a payoff matrix A for three assets across three states of the world, how would you express a portfolio constraint in matrix form, such as requiring non-negative payoff in every state?

“This one required more care than I initially gave it.”

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IMC·Software Engineer·Onsite - System Design / Architecture

May 2026
IMC system design round for a software engineer role. The whole thing was basically one big question about building a hotel booking system in memory, no database allowed. Decent problem but it goes deep fast.
  • Design a hotel booking system using only in-memory data structures. It needs to support adding hotels and room types, searching availability over a date range, creating and canceling bookings, and preventing double-bookings under concurrent load.

“This one sprawls.”

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IMC·Software Engineer·Recruiter / HR Screen

May 2026
Behavioral screen for a quant trader role at IMC. Just one question but it was the whole conversation, so you better have a real answer ready.
  • Why do you want to be a trader specifically, rather than going into quant research or software engineering?

“I had an answer but it felt thin the moment I started talking.”

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IMC·Software Engineer·Technical Phone Screen

May 2026
IMC software engineer interview with a systems theory question that felt deceptively simple but had a lot of nuance underneath. Not a grinding leetcode session, more of a conceptual discussion about how threading actually works in practice.
  • Is multithreading always faster than single-threaded execution? Explain your reasoning and walk through a concrete example.

“I started confidently saying 'no, not always' which was right, but then I fumbled the explanation a bit.”

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IMC·Machine Learning Engineer·Technical Phone Screen

May 2026
Conceptual ML interview at IMC for a machine learning engineer role. Two main topics came up: linear regression fundamentals and transformer architecture. Pretty theory-heavy, no coding, just talking through derivations and design decisions.
  • Derive the closed-form solution for ordinary least squares linear regression and walk through the assumptions behind it.
  • How do L1 and L2 regularization change the linear regression objective, and what are the practical differences in the solutions they produce?
  • Explain the bias-variance trade-off in the context of linear regression.
  • Walk through how self-attention works in a transformer, including the roles of queries, keys, and values.
  • Why is the computational cost of self-attention quadratic in sequence length, and how does that compare to RNNs for long contexts?
  • What are the main transformer variants (encoder-only, decoder-only, encoder-decoder) and when would you use each?
  • What is the purpose of positional encodings in a transformer, and how do residual connections and layer normalization contribute to training stability?

“I got through the normal equations fine but stumbled a bit explaining exogeneity vs homoscedasticity in plain terms.”

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IMC·Software Engineer·Technical Phone Screen

Jun 2026
IMC software engineer interview with a tree traversal problem that looks straightforward until you actually think about the constraints. One question, but it had enough depth to keep me busy for a while.
  • Given a rooted tree representing a company org chart, and a command issued by some person u, the command propagates to all of u's descendants in DFS preorder with children visited in ascending id order. Find the k-th person (1-indexed) to receive the command, or return -1 if there are fewer than k descendants.

“My first instinct was to just simulate the DFS and stop at the k-th node, which works fine for small inputs.”

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IMC·Machine Learning Engineer·Technical Phone Screen

Jun 2026
IMC ML Engineer interview with a market-making probability puzzle that looked straightforward until the follow-ups hit. The math is clean on paper but the conditional probability extension and the exponential distribution variant both require you to actually know what you're doing, not just memorize a formula.
  • You're a buyer in a market-making scenario. Each item is defective with probability 0.7 (worth 7000 to you) or genuine with probability 0.3 (worth 10000 to you). Defective sellers only sell if you bid at least 3000; genuine sellers only sell if you bid at least 7000. You can't observe the item type before bidding. What single bid maximizes your expected profit?
  • Now suppose you observe a partial signal about the item before bidding. Re-derive the optimal bid using conditional probability based on that signal.
  • Replace the discrete item values with values drawn from an exponential distribution and redo the expected profit analysis. How does your bidding strategy change?

“The key branch is whether to bid in the 3000-6999 range or go up to 7000+.”

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IMC·Software Engineer·Technical Phone Screen

Jun 2026
Got a coding question at IMC for a Machine Learning Researcher role. Pretty algorithmic, not much ML flavor to it, which surprised me a little.
  • Given an array of distinct integers and a target value, return all unique combinations of numbers from the array that sum to the target. A number can be reused any number of times.

“Classic backtracking problem.”

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IMC·Software Engineer·Online Assessment (OA)

Jun 2026
Video assessment round for a quant trader role at IMC. Just one behavioral question but the format is tighter than it sounds since you're on camera with a strict time limit.
  • What's your biggest achievement to date? Walk through the context, your goal, what you personally did, and the measurable result. You have roughly 2 minutes.

“The time cap is the real problem here.”

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