Susquehanna International Group Data Scientist interview questions & guide 2026

The following questions are representative of what you will face during the Susquehanna International Group interview process. These questions are drawn from real candidate experiences and are designed to test your core mathematical capabilities, quick decision-making, and logical reasoning under intense time pressure.

Probability & Combinatorics

As a quantitative firm, SIG places immense weight on your mastery of probability theory. You must be able to perform rapid calculations and structure your thoughts clearly.

• What is the probability of getting a Head-Tail-Head (HTH) sequence before a Head-Head-Tail (HHT) sequence when flipping a fair coin repeatedly?
• You are flipping a fair coin. What is the expected number of flips required to get two consecutive heads?

To succeed in the SIG Data Scientist interview process, you must shift your mindset from standard tech-company data science prep to highly rigorous quantitative finance prep. SIG cares deeply about your fundamental mathematical capabilities and your speed of execution.

Mathematical Rigor & Speed – You must be exceptionally fast and accurate with mental math, probability, and combinatorics. The firm values candidates who can calculate expected values, conditional probabilities, and permutations instantly without relying on calculators or writing down extensive notes.

Structured Problem-Solving – When faced with a complex brain teaser or probability puzzle, your interviewer wants to hear how you think. You should explicitly state your assumptions, break the problem down into smaller components, and explain your logical progression step-by-step.

Game-Theoretic Mindset – SIG has a strong gaming culture (poker, chess, and board games are highly celebrated). You must demonstrate an understanding of risk management, expected value, bankroll management, and competitive decision-making.

Cultural Alignment & Motivation – You need a compelling answer for why you want to work at SIG specifically, and why you are drawn to the trading floor environment. Showing a passion for competitive games, market dynamics, and fast feedback loops is highly valued.

The interview process for a Data Scientist at Susquehanna International Group is highly structured, rigorous, and typically spans 4 to 8 weeks. It is designed to filter for exceptional mathematical talent and quick decision-making capabilities.

The journey begins with an automated Online Assessment (OA), which serves as a strict filter. Candidates who pass the OA move on to a recruiter phone screen, followed by multiple rounds of intense technical interviews with quantitative researchers, traders, and software engineers. The process often includes an open-ended take-home data exercise before culminating in a multi-round superday.

The visual timeline above outlines the typical progression of a candidate through the SIG recruiting pipeline. It starts with the initial screening phase (OA and recruiter call), transitions into deep-dive technical evaluations, and concludes with a comprehensive onsite superday. Candidates should expect a consistent focus on mathematics and probability at every single stage of this process.

Probability and Statistics

This is the most critical evaluation area in the entire SIG interview process. You will be tested on these concepts in the online assessment, the recruiter phone screen, and every subsequent technical interview.

Be ready to go over:

• Conditional Probability & Bayes' Theorem – Calculating updated probabilities as new information becomes available, particularly in sequential game or coin-tossing scenarios.
• Expected Value & Variance – Finding the expected outcome of complex games, betting structures, or random walks.

As a Data Scientist at Susquehanna International Group, your day-to-day work will be highly dynamic and directly aligned with the firm's trading operations.

• You will collaborate directly with Traders and Quantitative Researchers to analyze high-frequency market data, identify inefficiencies, and design quantitative trading strategies.
• You will design, build, and maintain robust predictive models using advanced statistical machine learning techniques to forecast asset prices, market volatility, and liquidity.
• You will write high-performance Python or C++ code to implement trading algorithms, backtest strategies on historical data, and optimize execution systems.
• You will participate in daily trading desk discussions, offering data-driven insights to help traders manage risk and capture market opportunities in real-time.
• You will continuously research alternative datasets, market structures, and mathematical modeling techniques to keep the firm's trading strategies highly competitive.

SIG looks for candidates with exceptional quantitative pedigrees, a passion for problem-solving, and a competitive drive.

• Must-have skills – Exceptional mental math capabilities, deep mastery of probability theory and statistics, strong proficiency in Python (including libraries like NumPy, Pandas, and Scikit-Learn), and the ability to communicate complex mathematical concepts clearly.
• Nice-to-have skills – Prior experience in quantitative finance, knowledge of stochastic calculus or option pricing theory, familiarity with C++, and a strong background in competitive gaming (such as poker, chess, or competitive programming).
• Experience level – SIG heavily recruits PhD and Master's candidates from highly quantitative disciplines (such as Physics, Mathematics, Statistics, Computer Science, or Quantitative Finance), but also values experienced professionals with a proven track record of solving hard quantitative problems.

Q: How difficult is the Online Assessment, and how should I prepare for it? A: The OA is notoriously difficult due to strict time limits (typically 17 questions in 60 minutes). The questions cover combinatorics, probability, and logic puzzles. To prepare, practice solving math competition-style problems and probability puzzles under timed conditions without using a calculator.

Q: Does SIG require prior financial experience for the Data Scientist role? A: No. SIG cares far more about your core mathematical talent, logical reasoning, and coding capabilities. They have an industry-leading internal training program that will teach you the necessary financial and option-pricing concepts once you join.

Q: What is the culture like on the trading floor for Data Scientists? A: The culture is highly meritocratic, collaborative, and fast-paced. There is very little hierarchy, and decisions are made based on data and logical merit. The environment is competitive but friendly, with a strong emphasis on continuous learning and game theory.

Q: Where are the primary locations for this role, and is there a relocation requirement? A: The primary global headquarters is in Bala Cynwyd, PA (just outside of Philadelphia). There are also offices in New York, Sydney, Dublin, and London. Depending on the desk, some roles may require you to spend your first year at the headquarters in Pennsylvania for training and integration.

• Verbalize your thought process: During the technical phone screens and interviews, never solve a problem in silence. Explain your assumptions, state your intermediate calculations, and walk the interviewer through your logic. They care more about how you solve problems than just getting the final number.
• Embrace hints gracefully: If you get stuck on a difficult probability puzzle, the interviewer will often give you a hint. Do not panic. Listen carefully, incorporate the hint into your framework, and show that you can adapt your thinking quickly under pressure.

• Show your passion for games: If you play poker, chess, or strategic board games, be prepared to discuss them. SIG values the decision-making skills, risk management, and competitive drive that these games develop.
• Be decisive but risk-aware: In market-making simulations, do not be afraid to make a trade or quote a price. However, ensure you can mathematically justify your risk exposure and explain how you would manage your position if the market moves against you.

A Data Scientist role at Susquehanna International Group is one of the most intellectually stimulating and financially rewarding positions in the quantitative space. It offers a unique opportunity to apply cutting-edge statistical modeling and mathematical theory to real-time, high-stakes financial markets. The interview process is highly challenging, but it is also transparent, fair, and designed to find truly exceptional quantitative minds.

To maximize your chances of success, focus your preparation heavily on probability theory, combinatorics, and quick mental calculations. Practice structuring your thoughts aloud and reviewing classic quantitative finance puzzles. With focused preparation, a game-theoretic mindset, and a passion for fast-paced problem-solving, you can stand out in this competitive pipeline.

The salary insights module above displays the competitive compensation structure at Susquehanna International Group. As a data-driven firm, SIG rewards top-tier quantitative talent with highly competitive base salaries and substantial performance-based bonuses. When preparing your career strategy, keep in mind that the total compensation package at proprietary trading firms is heavily tied to both individual and firm performance, reflecting the high-impact nature of the Data Scientist role. You can explore additional detailed interview reviews, salary data, and prep resources on Dataford to help you ace your upcoming rounds.