Full Stack C# Developer

Job title: Full Stack C# Developer

About the Role

Join Marex's Enterprise team working on Engine Room, one of Marex’s most strategic technology initiatives. As a Full Stack C# Developer, you’ll help build and evolve a modern, enterprise-grade platform at the core of the business. We’re growing quickly and need energetic, flexible thinkers who can respond to changing demands, work collaboratively, and bring ideas to the table.

What You'll Do

• Design, develop and maintain high-quality C#/.NET solutions within the Engine Room platform.
• Contribute to the development of shared enterprise capabilities including API gateways, centralised APIs, real-time data streaming, connectivity frameworks and AI-enabled services.
• Build scalable, resilient and high-performance services that support multiple business streams across Marex.
• Collaborate closely with product owners, architects and other engineering teams to translate business requirements into robust technical solutions.
• Contribute to architectural design discussions and help shape platform standards, patterns and best practices.
• Ensure solutions are secure, observable and aligned with enterprise governance and regulatory requirements.
• Support the continuous improvement of CI/CD pipelines, automated testing and DevOps practices.
• Participate actively in team discussions, technical brainstorming sessions and knowledge sharing. Adapt quickly to changing priorities and evolving business demands in a fast-paced environment.
• Provide support and troubleshooting for production systems where required, ensuring high availability and reliability.
• Contribute to documentation and maintain clear technical artefacts to support long-term platform sustainability.
• Promote a collaborative, inclusive and high-performing team culture.
• All staff: Ensure compliance with the FCA regulatory requirements and internal policies; report breaches or risk events as required.

What We're Looking For

• Strong commercial experience in C# and .NET (Core / .NET 6+).
• Experience building RESTful APIs and microservices in enterprise environments.
• Good working knowledge of React and modern front-end development principles.
• Experience working with AWS cloud services (e.g. ECS/EKS, Lambda, S3, RDS, API Gateway).
• Experience with event-driven architectures, ideally using Kafka.
• Understanding of CI/CD pipelines, automated testing and DevOps practices.
• Experience with Infrastructure as Code, ideally Terraform.
• Strong understanding of software design principles (SOLID, clean architecture, domain-driven design concepts).
• Experience working in Agile/Scrum delivery environments.

Nice to Have

• Working knowledge of Node.js and/or Python.
• Experience building or contributing to enterprise platform or shared services environments.
• Exposure to API gateway technologies and distributed systems design.
• Experience implementing observability tooling (logging, monitoring, tracing).
• Financial services or capital markets experience (advantageous but not essential).
• Experience using CDM as a data model (advantageous but not essential).

Compliance & Conduct

• Demonstrates integrity, adheres to regulatory requirements, and complies with internal policies and FCA Code of Conduct.