Senior C# Engineer (Trading Systems)

Want to work on FX electronic trading systems at a top N. American Bank?

This isn’t just another dev role. It’s your chance to engineer the core of global trading.

We’re talking ultra-low-latency architectures, real-time market data, and speedy electronic trading, all in an environment where milliseconds matter, and billions move. You’ll work on building FX (forex) electronic trading systems.

If you thrive on complexity, love solving performance challenges under pressure, and want to collaborate directly with traders and product teams at the sharp edge of financial technology, this is your arena.

The Role at a Glance

• Senior C# .NET Backend Engineer

• Building a trading systems, including high-performance backend services for market data and electronic trading

• Fully remote for a top N. American bank (for residents of Poland only)

• Part of the core team - this is not a legacy support role or an outsourced B team

This role requires experience building trading systems, and an understanding of financial markets. An ideal candidate will have worked on FX trading systems.

If you enjoy working on low-latency, high-throughput trading systems, join us and build the next generation of high-performance capital markets solutions.

Why Join Us?

• Work on a large-scale, low-latency trading system.

• No Legacy: Join an actively developed system. The engineers who built it originally are still on the team.

• Collaborate with a world-class team of developers across North America and Europe.

• Enjoy the stability of a long-term, fully remote role that only a bank can offer.

A successful candidate will be a very strong programmer with current C# development experience. They must also be curious, open-minded, and desire to learn new things. English proficiency is a must. If you’re fascinated by understanding systems ‘under the hood,’ this role is for you. Successful candidates enjoy geeking out about data structures and debugging application performance issues.

This is a fully remote role for a developer in Poland. You will be working through a Polish company that will provide the support and administrative assistance to make you successful in the role. We are looking for people to join the team long-term.

Only open to residents of Poland. Polish citizens, as well as legal residents with permission to work in Poland, are welcome.

What we offer

• Work that matters in the financial domain: You’ll be building a high-performance trading system at an established financial institution.

• Professional growth: Collaborate with smart, highly capable developers in a supportive and challenging environment.

• Direct collaboration: You will work directly with the client team in North America and in Poland.

• 1st-tier work: This is not a technical support or legacy maintenance role. The system is functional and is actively being built and you will take part in updating it. The people who built the system are still part of the team.

• Long-term commitment: This is not a fixed-scope or fixed-term outsourcing role; we value people who want to grow and contribute long-term.

• Flexibility & remote work: Fully remote position based in Poland.

• Competitive Compensation: Top pay and ample time-off options.

Responsibilities

• Design and implement robust software solutions for FX trading systems using C# .NET.

• Collaborate with other teams to research and implement changes to the trading system.

• Create thorough test cases to ensure software stability and reliability.

• Collaborate with operations teams regarding building new features and improving existing functionality.

• Support production issues, including independently completing root-cause analysis and diagnosis.

• Process business requirements with minimal guidance, derive implementation proposals, and implement them with a team or individually.

• Mentor junior developers.

Requirements

Must have

• 7+ years of professional C# .NET development experience, with a strong understanding of programming concepts, including algorithms, complexity, and multi-threading, and Java’s language capabilities and standard libraries.

• Good knowledge of the data structures: familiarity with the .NET collections library, depth of understanding of the commonly used data structures, and intuition on what to use when.

• Proven experience building backend services for front-office trading systems.

• Deep understanding of front-office workflows and electronic trading platforms (any asset class).

• Built or contributed to the development of an electronic trading system (any asset class).

• Expertise in multi-threading, event-driven systems, and performance tuning.

• Ability to break down complex workflows into maintainable, high-quality solutions.

• Strong communication skills and comfort working in high-stakes, trader-facing environments.

• Knowledge that is required for building low-latency (measured in microseconds) trading systems.

• Familiarity with the FIX protocol.

• Ability to align your work with a 6-hour overlap with US Eastern business hours.

Nice to have

• Familiar with Broadway FX.

• Familiar with Java.

• A computer science degree from a top Polish school.

The recruitment process

1. Submit your CV.

2. Answer a few written questions and a short programming exercise which you can do at your own pace.

3. Participate in a three-stage interview process:

   • Written screen

   • Technical screen interview

   • Three technical interviews with future team members

     • Discuss your experience and skills.

     • Solve verbal algorithm problems (focus on clarity and understanding).

     • Tackle live coding challenges (no trick questions).

Successful candidates will need to pass a standard background check.