Senior C# .NET Core API Lead – WFH to £85k

Client Server Limited; Bracknell; Hybrid; GBP 75,000 - 85,000; Full time

Benefits offered by this job

Bonus

Pension

Life Assurance

Income Protection

Critical Illness Cover

Job summary

Client Server Limited is seeking a backend Software Developer/Engineer in Bracknell (WFH to £85k) to contribute to a major rebuild of a leading international payments platform. You will design and implement robust APIs and backend services using C# .Net Core, work on SQL databases, and apply strong architecture principles across microservices in a cloud environment.

You will join a small autonomous team of 4–6 engineers, mentoring peers and delivering new capabilities from design through

Qualifications

• Proven backend development experience with C# .Net Core.
• Experience designing and building production APIs.
• Strong SQL database design and query optimization.
• Experience with microservices and event-driven architectures.
• Familiarity with AWS or other cloud platforms.
• Mentoring and sharing technical knowledge with peers.
• Hands-on experience using AI coding tools such as Claude or Copilot.

Responsibilities

• Lead delivery of new backend features from design to production.
• Design robust, scalable APIs and backend services.
• Mentor engineers and promote technical best practices across the team.
• Collaborate on system design and architectural decisions.

Skills

C# .Net Core

APIs design

SQL

System design

Microservices

AWS

Mentoring

AI tools (Claude/Copilot)

Tools

Claude

GitHub Copilot

Job description

Client Server Limited is seeking a backend Software Developer/Engineer in Bracknell (WFH to £85k) to contribute to a major rebuild of a leading international payments platform. You will design and implement robust APIs and backend services using C# .Net Core, work on SQL databases, and apply strong architecture principles across microservices in a cloud environment.

You will join a small autonomous team of 4–6 engineers, mentoring peers and delivering new capabilities from design through