Chicago Trading Company

Large Enterprises

Screna has 3 Chicago Trading Company interview write-ups. The most reported round is the technical phone screen (2).

3 interview notes · updated Jul 2026

Chicago Trading Company·Software Engineer·Technical Phone Screen

Jul 2026

First technical round at Chicago Trading, 60 minutes, focused entirely on implementing standard C++ constructs. Pretty much exactly what people on the forums said to expect, so no real surprises if you did your homework.

Implement a unique_ptr from scratch.
Implement a vector from scratch.
What is the difference between move semantics and copy semantics in C++?

“This is a known ask for this company so I'd practiced it.”

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Chicago Trading Company·Software Engineer·Online Assessment (OA)

Jun 2026

Short Codility OA for a software engineer role at Chicago Trading. One coding question, 20 minutes, pretty straightforward Python problem.

Write a function that merges multiple Python dictionaries into one, handling key collisions however you see fit.

“Flat dicts only, no recursion needed, so the core logic isn't complicated.”

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Chicago Trading Company·Software Engineer·Technical Phone Screen

Jun 2026

C++ debugging round at Chicago Trading. One question, ten test cases, two bugs to find. More reading than coding, which I did not expect going in.

You are given a C++ order book implementation with ten test cases. Find and fix exactly two bugs so that all ten tests pass.

“Way more reading than I anticipated.”

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