C# Full-Stack Developer Experienced Hire

At Susquehanna International Group our technologists play a critical role in shaping the future of electronic trading. We build high-performance systems designed to compete in some of the most demanding and latency-sensitive markets in the world. Our developers collaborate closely with quantitative researchers and infrastructure teams to solve complex technical and strategic problems that drive significant business impact.

We are looking for a full-stack developer with strong proficiency in C#/.NET to join a fast-paced iterative development team delivering business-critical systems. This role suits a pragmatic technologist who understands end-to-end system impact communicates clearly and delivers business value quickly without compromising long-term stability.

Successful candidates balance technical excellence with practical decision-making take ownership of their work and collaborate closely with both technical and business stakeholders.

Key Responsibilities

Design build and maintain robust full-stack applications using C#/.NET and related technologies

Operate in an iterative development environment using lightweight specifications and fast feedback loops

Collaborate closely with traders business users support teams and fellow developers

Contribute to system and application architecture with a focus on scalability resilience and performance

Take ownership of systems across the full lifecycle from requirements and design through to production support

Support production environments at 2nd level ensuring system stability and prioritising operational improvements

Participate actively in design discussions reviews and knowledge-sharing sessions

Apply pragmatic decision-making guided by speed capacity stability and risk

Skills and Experience

Proficiency in C#/.NET and WPF

Experience in at least one additional programming language (e.g. Python or JavaScript)

Solid understanding of software design debugging and problem solving

Experience working with distributed systems and business-critical applications

Familiarity with modern development tools and practices (e.g. Git-based workflows CI/CD)

Experience working across the full software development lifecycle including production support

Strong written and verbal communication skills particularly in collaborative fast-moving environments

Personal Attributes

Pragmatic and delivery-focused without sacrificing code quality or long-term maintainability

Strong sense of ownership and accountability

Clear concise communicator with good judgment on when and how to engage others

Curious adaptable and motivated to understand both technical systems and business context

Collaborative professional and resilient under pressure

Nice to Have

Experience in financial trading or time-sensitive environments

Exposure to cloud platforms containerisation or system monitoring

Experience with databases and writing complex queries

Experience in software performance tuning for high throughput or low latency

Experience contributing to documentation mentoring or engineering standards

Equal Opportunity Statement

Were committed to building a diverse and inclusive workplace. We encourage candidates from all backgrounds to apply and are happy to provide reasonable accommodations during the hiring process.

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