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SIG Software Engineer Interview Guide

Understand the qualifications and background you need to become a software engineer at SIG.

Introduction

Susquehanna International Group (SIG) offers an exciting, lucrative, and dynamic career path for software engineers. As part of the software engineering team, your contributions will directly support the technology that powers SIG's trading and market making operations.

Within this guide, we will take you through SIG's values, work culture, and the career prospects of a software engineer. We'll also provide an overview of the key skills required, an in-depth look at SIG's interview process, and resources to help optimize your application.

Whether you're new to the industry or an experienced developer, we'll ensure you understand SIG's interview process, and that you are well-prepared to land your dream role as a software engineer at SIG. Enjoy!

Software Engineering at SIG

Susquehanna International Group is a global quantitative trading firm which trades many listed financial products and asset classes, with a focus on derivatives. SIG was founded in 1987, by a group of college students with a mission to find profit in the intersections of trading, technology, and research.

Fast forward to 2025 - SIG boasts an impressive 3000 employees in over 17 locations, including Philadelphia Area, New York, Chicago, San Francisco, Stamford, West Palm Beach, Dublin, London, Ra'anana, Sydney, Beijing, Hong Kong, Mumbai, Shanghai, Singapore, and Tokyo.

SIG values people who value reflection, growth, teamwork, and integrity. The firm places a heavy emphasis on good decision making, which is achieved through rigorous, analytical, and reflective approaches to problems. SIG also values perpetual curiousity and the challenging of ones own assumptions.

As a software developer at SIG, you will certainly not be short of challenges. This is a high-pressure, technically advanced position. SIG understands this, and has resources and systems in place to ensure that you can make the most of your skills, while practicing a sustainable lifestyle.

Your Background

To become a software engineer at SIG, you must meet a select number of prerequisites. However, please note that this is a competitive position, and you will need to go above and beyond with your qualifications and experience to stand out in interviews.

SIG lists the following as mandatory to be considered for a software engineering role:

Are working toward a Computer Science, Computer Engineering or a similar technical major, with a distinction average WAM
Are in the penultimate or final year of your degree
Strong software skills in C++, C#, Python and/or Java
Solid knowledge of algorithms, data structures, and object-oriented design patterns

To learn and reinforce your software skills and DSA knowledge, learn by doing with our courses in Python Programming for Traders, and Data Structures and Algorithms in Python.

To be more competitive within the interview process, consider these attributes and qualifications:

Experience in competitive and strategic environments to a high/professional standard (e.g. sports, chess, poker)
Strong software projects/employment in quantitative domains (e.g. Options pricing model, volatility estimator)
Advanced quantitative, logical, and problem solving skills
Has effective communication skills, and thrives working in a group setting
A strong passion for technology

Please note that these are a few attributes that would be beneficial to improve your chances of landing a quantitative trading position. There are multiple other experiences/qualifications that will also be beneficial, but the qualities from these attributes are highly valued at quantitative trading firms.

Your Application

The software engineering application process at SWE can be quite tricky and convoluted for first-timers. Therefore, it is imperative to study the application process to get a competitive advantage (like you are doing now, go you!).

You will be asked to fill out a range of questions, including your degree, your GPA, your graduation date, your resume, and so on.

The main focus is on your resume, which will contain your:

Career objectives and overview
Area of study and academic performance
Experience and projects
Extracurricular/competitive achievements
Characteristics and interests

It is important you structure your resume correctly. We recommend a platform such as resume.io to assist you with building your resume.

Round 1: Online Assessment

Your application will be screened, and if your meet the prerequisites, you will be sent an online assessment link. You will have a week to submit this online assessment. Within the online assessment, you must provide solutions two programming questions, in a language of your choice, within a 60 minute timeframe:

1. Programming Solution

You will have to write a programming solution for a given problem, typically as a function. You may be asked to use a specific algorithm, such as BFS or binary search, or come up with an innovative solution yourself. A few examples include Maximum Drawdown, Compound Interest, and Dijkstra.

2. Object-Oriented Programming

You may be asked to implement a class that contains specific methods, including getter, setter, and other methods which satisfy a particular purpose. An example may be creating a library class, which is able to hold a range of book classes, and filter books based on attributes like it's name, author, date, and so on.

For both of these questions, simply getting to a solution will not cut it! You must be considerate of which data structures you are using, the algorithms' time/space complexity, and whether you are using good programming practices. Try and find the most optimal answer with these considerations in mind.

To master SIG's software engineering online assessments, view our interview programming questions.

Round 2: HR Interview

If you are invited to this round, then SIG has deemed your software engineering skills sufficient. Congrats!

In your HR Interview, you and a recruiter (who has technical experience) will scrutinize your resume, and understand why you would like to work at SIG.

Be prepared to come across the following types of questions:

1. General Questions

General questions regarding your motivations, values, personality, and work style allow the interviewer to further understand how you will integrate into the work environment.

You can see examples of general questions and how to answer them effectively in our common general questions list.

2. Background Questions

These questions dive into your previous work experience, projects, and education to get a better understanding of how you qualify for the role.

To see these types of questions, view common background questions.

This interview section is very overlooked. Make sure you deeply understand the SIG's values and mission (as described above) before going into the interview.

Also, be authentic and confident yet humble, and prepare your experience and projects in a professional way.

Key tip: If you are a poker player, be sure to speak about this! SIG makes their interns and graduates learn poker theory. SIG also has many internationally successful poker players on their team!

Round 3: Technical Interview

You have made it to the penultimate round of SIG's software engineering program. Good work!

This technical examination lasts 90 minutes, where you will be interviewed by a software engineer at SIG. This interview relies on the application of computer science knowledge to reach abstract and innovative programming solutions. The exam is split into three sections:

1. Code Optimisation

Your interviewer will provide you with inefficient code with bad programming principles. Your aim is to optimise this code such that it's time and space complexity is optimised, and is more readable and reusable.

You will have to leverage your knowledge of Data Structures and Algorithms, as well as SOLID programming principles.

Once you have improved the code, the interviewer may ask you to improve it further, giving you hints if you are stuck. You may repeat this process several times, until the code reaches a valid state, judged by your interviewer.

2. Code Reflection

You will then be asked by your interviewer to assess the code. Why is the program better and more efficient? Why has the data structure you chose lead to better efficiency?

You must mention specifics in terms of time/space complexity of each data structure you use, and the algorithm. You must also answer any other programming related questions asked by your interviewer in general throughout this process.

To stand out, it would also be a good idea to reflect on your program development process. How did you approach the improvement process? What systems and methods do you have in place to improve codebases?

3. Object-Oriented Programming

Similar to the online assessment task, you may have to demonstrate your object-oriented programming principles, by programming an object from scratch.

As you create the class, the interviewer may ask you to add additional methods. Remember to be mindful of which data structures and algorithms you use, along with your programming practices.

Final Round: Office Interview

If you've made it this far, then you should be proud of yourself! You just need to ace one more interview, and you will be a software engineer at SIG.

In this final round, you will be located at their specified office. SIG will pay for your flights, and accomodation for your stay. This round usually takes the entire day, and is broken up into four sections:

1. HR and Software Engineer Discussion

This is a conversational, casual interview to get a sense of your passions, qualifications, experience, how you would contribute to SIG's mission, and SIG's work environment. You will be interviewed by a recruiter, as well as an experienced software engineer.

In this conversation, demonstrate your passion and curiousity for proprietary trading, financial markets, and technology. Ask insightful questions, regarding quantitative finance in general and exclusive insights into SIG. And don't forget to just be yourself!

2. Prorgamming

You will be tasked to write a programming solution for a given problem, typically as a function, to complete in front of a senior software engineer. Similar to previous rounds, you may be asked to use a specific algorithm, such as BFS or binary search, or come up with an innovative solution yourself. The problem may be solvable within a function or a class.

Once again, the interviewer will be getting a grasp of your computing, DSA, and progamming principles knowledge,

3. System Design and Architecture

System design is perhaps the hardest element of SIG's software engineering final round interview. You may be asked questions such as, "How would you design a market data feed system that ingests and processes stock prices, option prices, and other market data in real-time?".

You will have to discuss specifics within your solution, describing:

High-Level Design: Core concepts, icluding Data Processing, Notification Systems, API Gateways, Databases, etc. Clearly define how these components will interact with each other (e.g. data flow, synchronous vs asynchronous communication, etc)
Data Storage: How will the data be stored? Choose the right database based on the structure and needs of your data.
APIs & Microservices: What APIs do you need to connect with your system?
Scalability: Horizontal vs vertical balancing, load balancing, caching, partitioning.
Edge cases: How may this system fail is certain circumstances? Address these special cases.

For the system design section, it is super important you understand basics of networking protocols, TCP/UDP - their tradeoffs, and where they are used. You may also have to perform back-of-the-envelope calculations to estimate the system's capacity and/or performance.

4. Project Deep Dive

In this interview, you go over a technical project that you have worked on in detail. You will have to explain the reason you made it, what problem it solves, what libraries and algorithms you used, and a demonstration of the working product.

Make sure you know your projects inside out! Often when you finish a project, you may forget how you solved specific problems. Make sure you remember your entire codebase/project base.

Success and Beyond

If you have made it this far, then congratulations! You have been selected to be a software engineer at SIG.

However, despite coming so far to reach this point, it's certainly not the end of the struggle within your quantitative journey. If you are accepted into the internship program, you must stand out within your technological domain in order to recieve a graduate offer.

Stay humble throughout your first few weeks of SIG, stay dedicated on your journey for continuous learning, and keep an open mind throughout your quantitative career. But for now, celebrate, because you truly deserve it!

Closing Remarks

If you are feeling quite overwhelmed by the complexity and length of SIG's software engineering interview process, that is totally normal! By reading this, and understanding the interview process holistically, you have already gained a competitive advantage over most applicants.

To gain an even further advantage in the interview process, it is imperative that you start preparing early and stay consistent in your preparation. Many applicants fail to delegate adequate time for interview preparation, or overlook interview preparation in general, leading to their absolute demise in the interview process.

For competitive jobs, interviewing is a must-have skill. Please understand, software engineering at quantitative finance firm is super competitive, with only a select few that will fill in positions. To stand out, and maximise your chances of securing your dream position, you must prepare early.

Further, if you feel that you're not up for a software engineering position at SIG, the biggest mistake you can do is not apply! You miss all opportunities you do not take. And understand that all successful software engineers in ALL industries have imposter syndrome at several points within their career.

Overall, becoming a software engineer at SIG is a highly exhillerating and fulfilling career path, and with enough preparation and knowledge, you will be well-positioned to crack the interview process, and land the position.