Susquehanna International Group (SIG) is a trading firm headquartered near Philadelphia, known for options market making and a culture that uses games and decision theory to train traders. Engineers face coding and systems interviews; traders face probability and game-based questions. This page covers what Susquehanna (SIG) builds and who it hires, the process candidates commonly report, the technical depth the teams care about, representative problem types, what interviewers score, and a three-week prep plan.
What Susquehanna (SIG) builds and who it hires
SIG's technologists build trading systems, research platforms and infrastructure across many asset classes. Traders and quantitative researchers make decisions under uncertainty, which is why probability shows up so often in its interviews.
- Software developers: trading and research systems.
- Quantitative developers and researchers: models and data.
- Traders: options and market making.
- Infrastructure engineers: networks, systems and data.
What the process tends to look like
| Stage | What happens | How to prepare |
|---|---|---|
| Online assessment | Commonly reported: an online assessment of coding problems for technology roles | Timed problems with hidden test cases; check edge cases before submitting |
| Phone or video interviews | Technical interviews on data structures, algorithms and design | Explain approach and complexity before coding |
| Final round | A final round with several interviews, often including a design discussion and team fit | Rehearse systems depth and one project deep dive |
Processes differ by team, level and office and change over time, so treat this as the common shape candidates report and confirm the specifics with your recruiter.
Coding, probability and games
Clean, correct code. Technology interviews reward working code with tests and clear reasoning more than clever tricks.
Probability for trading roles. Trader and research roles add expected value, conditional probability, quick estimation and betting or market-making games; even engineering candidates sometimes get a light version.
Decision-making. Expect questions where you must decide with incomplete information and explain how you would update as you learn more.
Representative problem types
These are the kinds of problems candidates describe, not a leaked question list. Practice the category, not the exact question.
- Implement an LRU cache with constant-time operations.
- Design a system that prices options as market data changes.
- Find arbitrage in a table of exchange rates.
- Expected value of a dice or card game, then a variant.
- Design a logging pipeline that must not lose trades.
- Interval and scheduling problems.
- Medium algorithm problems in your strongest language.
What interviewers score
- Correctness first: edge cases, overflow and off-by-one errors matter more here than elsewhere, because a bug costs money.
- Speed of reasoning: how quickly you reach a correct approach and how you check it.
- Low-level understanding: what your code costs in memory, cache misses and system calls.
- Clear thinking under pressure: saying what you are unsure of and how you would test it.
The behavioral side
Technical rounds decide most outcomes, but every Susquehanna (SIG) loop also asks about how you work. Prepare a short story for each of these, with a result and what you learned:
- A mistake you made and what you changed. Trading firms value people who own errors quickly, because errors cost money.
- A decision under uncertainty. Explain what you knew, what you did not, and how you updated.
- Why trading, and why this firm? Be specific about the problems that interest you: speed, markets, research or infrastructure.
Structures and sample answers for the common questions are in our software engineer behavioral answers guide.
A three-week prep plan
- Week 1: algorithms at speed: two medium or hard problems a day under a 30-minute limit, with complexity stated aloud.
- Week 2: systems depth: C++ memory and object layout, concurrency primitives, Linux and networking basics, plus probability practice if the role touches trading.
- Week 3: mixed mock interviews, one per day, and a review of every bug you made so you stop repeating them.
For other trading firms, compare Jane Street, Citadel and Two Sigma, and read the Citadel online assessment for a typical HackerRank screen.
Where CoPilot Interview fits
Most of a Susquehanna (SIG) loop is spoken: you explain an approach, defend a trade-off and talk through your past work. CoPilot Interview is an AI interview assistant whose free AI mock interview builds technical and behavioral questions from your résumé and the job description, reads them aloud and scores each spoken answer out of ten, so you can rehearse the explanation as well as the code. The free plan gives 15 minutes a day of live help in sessions of up to 15 minutes, with AI mock interviews included. Online assessments and many coding rounds forbid outside help, so practice beforehand and follow your employer's rules on the day.
Disclosure: CoPilot Interview is our product, so weigh what we say about it accordingly.
Frequently asked questions
What programming language should I use in a Susquehanna (SIG) interview?
Technology teams use several languages, including C++, C# and Python; check the job description and ask which language the screen uses.
Does Susquehanna (SIG) send an online assessment?
Technology applicants commonly report an online assessment early in the process. Trader applicants report math and probability tests instead.
How should I prepare for Susquehanna (SIG) coding questions?
Practice the problem categories above under time limits, explain every solution out loud, and spend the last week on the team's domain. Review the C++ or language fundamentals the role lists, because Susquehanna (SIG) interviewers tend to follow a working solution with questions about cost and trade-offs.
Can I use AI tools in a Susquehanna (SIG) interview?
Only if the instructions you receive say so. Online assessments and live coding rounds generally forbid outside help, and some companies now state their AI policy in the invitation. Use AI to practice beforehand, and follow your employer's rules.
Practice this interview before the real one
The AI mock interview builds questions from your resume and the job description, reads them aloud and scores each spoken answer out of 10. Included on the free plan.
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