Senior Backend Engineer (.NET Core) – Fintech / Payments

We are looking for an experienced Senior Backend Engineer to join an engineering team building secure, scalable systems within the fintech space. This role is suited to a backend specialist with strong .NET Core experience who enjoys working on complex, high-throughput platforms where performance, reliability, and security are essential.

You will contribute to the design and evolution of backend services, work on distributed systems, and help maintain high engineering standards across the team.

Key Responsibilities

• Design, develop, and maintain secure, high-performance backend services using .NET Core
• Build, evolve, and maintain RESTful APIs
• Contribute to microservices-based and distributed system architectures
• Work across both greenfield and existing systems with a focus on scalability and maintainability
• Participate in technical design discussions and influence engineering best practices
• Optimise database performance, queries, and data access patterns
• Identify and resolve performance and reliability issues
• Collaborate closely with product, frontend, and QA teams in an Agile environment
• Participate in code reviews and support continuous improvement

Skills & Experience

• Strong commercial experience as a Senior Backend Engineer using .NET Core
• Proven experience building scalable backend systems in production environments
• Experience designing secure, high-performance RESTful APIs
• Solid understanding of distributed and asynchronous backend systems
• Experience working with cloud platforms such as AWS or Azure
• Strong SQL Server experience, including query and performance optimisation
• Experience with ORMs such as Entity Framework Core or Dapper
• Exposure to message-based or event-driven systems (e.g. RabbitMQ, Kafka)
• Experience with automated testing frameworks (e.g. xUnit, NUnit)
• Comfortable working in Agile delivery environments
• Strong problem-solving and communication skills

Nice to Have

• Experience working in the payments or broader fintech domain
• Exposure to highly regulated or high-availability systems
• Mentor junior and mid-level engineers

Location & Working Pattern

• Central London office
• Hybrid working: 3 days per week on-site

There is a 2 - 3 stage interview process with interview slots now available.

Apply now to be considered.