Susquehanna's Interview Process (2026)

Blog / Susquehanna's Interview Process (2026)

The Susquehanna software engineer interview process typically runs 4 to 5 stages, and most candidates report a noticeably stronger emphasis on low-level systems knowledge and performance optimization than you'd find at a standard tech company.

Recruiter Screen: Usually a 30-minute phone call covering your resume, your motivation for joining a quantitative trading firm, and general behavioral questions. Some recruiters include light filter questions on operating systems or networking.
Online Assessment: A proctored coding assessment, typically delivered via CodeSignal or Mettl, with around 2 to 4 algorithmic problems. Candidates report that efficiency matters here, not just passing test cases.
Technical Phone or Zoom Screen: A live coding session in a shared editor, usually 60 to 90 minutes. Some candidates report a '30+30' format where you code solo for 30 minutes, then spend the remaining time reviewing and optimizing your solution with the interviewer.
Onsite or Superday: A multi-round loop that typically runs 4 to 5 hours and includes a deep-dive algorithmic session, a system design round, and several team-fit conversations. You may meet with engineers from different teams such as Options, Fixed Income, or Infrastructure.

To prepare effectively, focus your study plan across these key areas that Susquehanna consistently emphasizes for SWE candidates:

Data Structures & Algorithms (DSA): Algorithmic problem-solving with a strong focus on optimization and efficiency.
System Design: Low-latency, deterministic system design for high-frequency, performance-critical environments.
CS Fundamentals: Low-level systems knowledge including memory, concurrency, and how code interacts with hardware.
Behavioral: Team-fit conversations assessing collaboration, curiosity, and decision-making under uncertainty.

1. Data Structures & Algorithms (DSA)SIG's DSA rounds go beyond just arriving at a correct answer. Once you solve a problem, expect the interviewer to push you on how to make it faster and why your chosen approach is better for the hardware, not just on paper.Hashmaps, trees, and arrays come up frequently, and candidates report questions around custom data structures designed for high-frequency data scenarios. Practicing problems like Sub-array Sum Condition and Fraction Equality Most Frequent can help you build intuition for the types of problems SIG tends to surface.For broader preparation, work through our top 100 DSA questions to cover the most commonly tested patterns. Pay particular attention to trees and hashmaps, since these come up repeatedly in SIG interviews.

2. System DesignSIG's system design questions are not about building web-scale services with load balancers and sharding. The focus is on low-latency, deterministic design, think processing millions of market data updates per second with zero loss.Expect questions about memory management, garbage collection bottlenecks, lock-free concurrency, and how to avoid anything that could introduce unpredictable delays. Practicing the Stock Exchange (NASDAQ, NYSE) design problem is one of the most direct ways to prepare for the kinds of constraints SIG will throw at you.Brush up on High-Level Design concepts to build a solid foundation, and use our System Design AI Whiteboard to get comfortable drawing and communicating architectures under time pressure.

3. CS FundamentalsSIG interviews consistently reward candidates who understand what their code is doing at the hardware level. You should be ready to explain how a hashmap or list works in memory, what happens during a context switch, and how CPU cache behavior can make or break the performance of an algorithm.The optimization deep-dive round often presents a working but naive piece of code and asks you to refactor it for maximum performance. This means knowing about memory alignment, avoiding unnecessary allocations, and understanding cache locality, not just big-O complexity.Reviewing operating systems concepts will help you speak confidently about context switches, memory management, and concurrency. Pairing that with system design core concepts gives you the vocabulary to connect hardware-level thinking to architectural decisions.

4. BehavioralSusquehanna's behavioral rounds carry more weight than many candidates expect. Recent feedback from 2025 cycles shows that technically strong candidates were turned down after failing to demonstrate collaborative instincts or genuine curiosity in team-fit conversations.SIG's culture is deeply rooted in probabilistic thinking, so you may also be asked how you make decisions when you don't have all the information, or even asked to estimate your confidence in an answer. Think through how you reason under uncertainty and be honest about trade-offs rather than projecting false certainty.Prepare specific examples from your past work that demonstrate collaboration and intellectual curiosity. The Behavioral Interview Course is a good starting point, and structuring your answers using the STAR principle will help you stay concise and clear during the team-loop rounds.

ConclusionSusquehanna's SWE interview rewards candidates who can think below the surface, optimizing for hardware, reasoning under uncertainty, and writing clean, pragmatic code. Start with the fundamentals, practice the optimization mindset, and make sure your behavioral preparation is just as sharp as your technical skills. Follow the Susquehanna Interview Roadmap for a structured, stage-by-stage plan to get you ready.

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