Senior Software Engineer (.NET/AWS) Salary: Up to £110,000 Location: Central London (3 days per week in-office) A leading financial services technology organisation is looking for a Senior Software Engineer to help build and evolve high-performance, cloud-native systems that underpin critical pricing and trading workflows. This is a hands-on senior role where you''ll take ownership of Back End services, influence technical direction, and mentor other engineers, all while working with modern cloud and DevOps tooling. What you''ll be doing Designing, building and maintaining modern .NET services in a cloud-first environment Developing scalable, resilient microservices running on AWS Working closely with product, BA and delivery teams to turn complex requirements into clean, well-structured solutions Driving code quality, test automation and CI/CD best practices Monitoring and improving system performance, reliability and security Supporting and mentoring engineers across the team Tech environment (core focus) .NET/C# (modern versions) AWS (broad service usage, cloud-native design) SQL/relational databases (strong schema and query design required) Microservices architecture CI/CD pipelines andamp; Git-based workflows Nice-to-haves/big pluses Docker for containerisation Kubernetes (hands-on or strong working knowledge) Infrastructure as Code (eg AWS CDK, Terraform or similar) Experience in highly regulated or mission-critical systems What they'