Radix Trading Interview Process & Prep

Radix is a secretive Chicago HFT firm with a Quant Technologist model. Expect hard C++/algorithms, numerical-analysis problems (stable summation, catastrophic cancellation, custom allocators), plus probability and linear algebra. No game.

Quant TechnologistQuant Researcher

The Radix Trading interview funnel

1. Recruiter / Screen

Phone - background + fit

An intro conversation about background and interest, sometimes with a quick technical warm-up.

2. C++ & Algorithms

60-90 min - coding

C++ implementation and numerical problems: reference-counted shared_ptr, fixed-buffer allocator, stable summation (Kahan), tournament min-comparisons.

3. Probability & Numerical

45-60 min - video

Probability, combinatorics, and statistics with a numerical bent (variance computation, sampling).

4. Linear Algebra & Optimization

45-60 min - research

Linear algebra (eigenvalues, conditioning), optimization (LP/least-absolute-deviations), regression, and stochastic processes.

5. Onsite - Hardest Rounds

Final rounds - the toughest reported problems

The hardest reported Radix Trading problems across every topic. (Hard-rated only; earlier rounds cover easy/medium, so nothing repeats.)

Radix Trading interview — FAQ

What is the Radix Trading interview process?

Radix is a secretive Chicago HFT firm with a Quant Technologist model. Expect hard C++/algorithms, numerical-analysis problems (stable summation, catastrophic cancellation, custom allocators), plus probability and linear algebra. No game. The loop runs 5 stages: Recruiter / Screen, C++ & Algorithms, Probability & Numerical, Linear Algebra & Optimization, Onsite - Hardest Rounds.

How many rounds does Radix Trading have?

5 stages in total, starting with the Recruiter / Screen and ending with the Onsite - Hardest Rounds.

How do I prepare for the Radix Trading interview?

Work the stage notes above, then drill the Radix Trading interview-questions set and the Radix Trading online-assessment practice — each problem has a full worked solution.