15th January 2026
Senior Software Engineer – C#.NET
Engineering
London
Up to £110,000
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 & 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’re looking for
- Proven experience as a Senior .NET Engineer in complex, production environments
- Strong cloud engineering mindset with real-world AWS experience
- Someone who cares about clean code, testing and long-term maintainability
- Confident communicator who can work across technical and non-technical teams
- Comfortable balancing hands-on delivery with technical leadership
Why this role?
- Technically challenging systems with real business impact
- Modern cloud stack with room to influence architecture
- Sensible hybrid working: 3 days per week in a Central London office
- Competitive salary up to £110,000 plus benefits
Consultant - Seth Couch
Telephone: 0207 392 7503
Email: seth.couch@spencer-rose.com
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