Senior .NET Developer | Brighton (Hybrid) | £70,000 + bonus + benefits I''m working with a well-established, international E-commerce business in Brighton. Its booking platform processes thousands of transactions every day across more than 20 markets. The business is looking for a Senior .NET Developer who cares about building fast, reliable APIs at scale. The role You''ll work on a business-critical part of the platform. You''ll build, measure and tune services running in the cloud and at the edge, and you''ll own them from design through to production. You''ll be part of a multi-disciplinary team of engineers, SDETs, DevOps, product and UX, releasing several times a day through CI/CD. You''ll also have a real say in how things are built. What you''ll bring Strong commercial C# .NET Back End experience SQL Server/T-SQL, including query tuning, indexing and execution plans High-traffic E-commerce or transactional systems Cloud experience, ideally AWS Strong RESTful API design: versioning, idempotency, caching, OpenAPI/Swagger Production ownership: monitoring and profiling .NET apps (eg Datadog, New Relic, CloudWatch) Daily use of AI coding tools (Claude Code, Copilot, Cursor), with the judgement to own what they produce Good engineering habits: code review, automated testing, small and frequent releases Nice to have: a CS degree, and exposure to DDD, event-driven architecture, TDD/BDD, microservices or CQRS. Why join? It''s a pragmatic, evidence-led engineering culture. ..... full job details .....