Full Stack C# .NET Developer | Core Trading Systems | Kafka Hybrid

Full Stack C# .NET Developer | Core Trading Systems | Kafka | Financial Services | Hybrid, London

A Full Stack C# .NET Developer is required to join a high-performing engineering team within a leading financial services firm operating across global markets.

This is a C# .NET–focused engineering role working on one of the firm’s most strategic technology initiatives, building and evolving core internal systems that underpin trading operations and support multiple business streams across the organisation.

You will be joining a technology-driven business that invests heavily in modern C# .NET engineering practices, scalable architecture, and cloud-native infrastructure with Kafka at the heart of how data moves across the platform.

The team sits at the core of the firm’s internal technology ecosystem. They design and build the systems responsible for:

• Delivering centralised C# .NET APIs and shared internal capabilities across trading and operations
• Building and operating real‑time data streaming pipelines using Kafka
• Enabling AI‑powered services built on modern .NET infrastructure
• Supporting trading workflows through scalable, resilient C# .NET platform services

The environment is event‑driven and Kafka‑based, built on modern .NET and AWS infrastructure. The team works closely with product owners, architects and business stakeholders to deliver C# .NET solutions that directly impact trading operations.

Hybrid working | London

As a Full Stack C# .NET Developer, you will:

• Design and build high‑quality C# .NET solutions within a Kafka‑driven, event‑driven architecture
• Develop scalable C# .NET streaming services and internal capabilities including API gateways, real‑time Kafka pipelines and AI‑enabled services
• Build resilient, high‑performance .NET backend services supporting live trading operations
• Architect and deliver robust C# .NET microservices that integrate seamlessly with Kafka event streams
• Contribute to architectural design, platform standards and C# .NET engineering best practices
• Ensure solutions are secure, observable and aligned with governance and regulatory requirements
• Support CI/CD pipelines, automated testing and Dev Ops practices across the .NET estate
• Collaborate closely with product owners, architects and engineering teams to translate business requirements into robust C# .NET technical solutions
• Contribute to documentation and maintain clear technical artefacts
• Mentor and review C# .NET code where required

• Strong commercial experience as a C# .NET Developer with proven .NET Core / .NET 5+ expertise
• Experience building RESTful C# .NET APIs and microservices in enterprise or trading 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)
• Hands‑on experience with Kafka or equivalent event‑streaming technologies within a .NET environment
• Understanding of CI/CD pipelines, automated testing and Dev Ops practices
• Experience with Infrastructure as Code, ideally Terraform
• Strong understanding of C# .NET software design principles (SOLID, clean architecture, domain‑driven design)
• Experience working in Agile/Scrum delivery environments
• Deeper Kafka experience including stream processing, consumer group management or Kafka Streams alongside C# .NET services
• Working knowledge of Python or Node.js/Type Script to complement core C# .NET skills
• Exposure to API gateway technologies and distributed systems design
• Experience implementing observability tooling (logging, monitoring, tracing) across .NET applications
• Financial services or capital markets experience (advantageous but not essential)
• Experience using CDM as a data model (advantageous but not essential)