Senior .Net Developer

Synnovate; United Kingdom; On-site; GBP 112,000 - 156,000; Full time

Job summary

Synnovate is seeking a Senior .NET Developer for a 9-month contract, fully remote in the United Kingdom. You will join a greenfield build of a large-scale platform, using modern patterns and AI-assisted development.

Expect to own significant backend work, build APIs, and design scalable data models while operating with minimal hand-holding. Strong expertise in .NET/C#, RESTful APIs, and SQL Server is required; experience with AI-assisted coding and containerisation (Docker/Kubernetes) is highly

Qualifications

• Strong .NET / C# proficiency with excellent skills.
• Experience with AI-assisted development (Copilot, Claude, Cursor, or similar).
• Experience designing RESTful APIs and working with SQL Server.
• Familiarity with containerisation and modern deployment tooling.

Responsibilities

• Build APIs and data models for a scalable platform.
• Design and implement business logic engines.
• Ensure the platform scales and can run in production.
• Own significant pieces of work with minimal supervision.

Skills

C#/.NET

AI-assisted development

REST APIs

SQL Server

Tools

Entity Framework

Docker

Kubernetes

Job description

Senior .Net Developer

My customer is looking for a Senior .Net Developer to join them on a 9 Month contract basis, Outside IR35 & working fully remote. AI assisted development will need to be at the forefront of how you develop, operate, and process your workload and coding tasks.

As the succesfull Senior .Net Developer you'll be joining a greenfield build of a large scale platform. This isn't maintaining legacy code, it's building something new from scratch using modern patterns and AI-assisted development. The platform already has a working prototype but you'll be taking it into production.

You’ll be working across the full stack of backend services: building APIs, designing data models, implementing business logic engines, and making sure the platform scales. You’ll need to be comfortable owning significant pieces of work with minimal hand-holding and making good technical decisions independently.

Must Have

• Strong .NET / C# — this is your primary skill and it needs to be excellent
• Demonstrable experience with AI-assisted development (Copilot, Claude, Cursor, or similar)
• Experience building and designing RESTful APIs
• SQL Server — comfortable with schema design and query performance

Strongly Preferred

• Entity Framework
• NoSQL (CosmosDB, MongoDB, or similar)
• Redis
• Authentication and authorisation implementation (OAuth, OIDC, RBAC)
• Containerisation (Docker / Kubernetes)

About the Person

The tech stack matters less than the person. We need someone who's sharp, pragmatic, and gets things done without needing to be managed. They should be comfortable in a small team where there's nowhere to hide and the pace is high. Someone who takes pride in building things properly but doesn't over-engineer. If they've worked in financial or regulatory systems that's a bonus but it's not required — we'll teach the domain.