Senior Software Engineer
Senior Backend .NET Engineer - Platform Modernisation
📍 Location: On‑site 4 days per week / 1 day remote
🕒 Contract: 12‑month rolling contract (full‑time)
💼 Engagement: Contractor
The Role
We are looking for a Senior Backend .NET Engineer to support and modernise a large, business‑critical platform used in a regulated environment.
Key Responsibilities
- Refactor and modernise an existing ASP.NET backend, replacing ASP.NET Boilerplate with standard .NET patterns and components
- Work extensively with C# and modern .NET, applying best practices around performance, reliability, and maintainability
- Design and optimise Entity Framework Core usage, including migrations, transactions, and query performance
- Analyse and improve SQL Server performance, including writing efficient queries and troubleshooting database issues
- Debug and resolve issues in a large, complex legacy codebase
- Collaborate with frontend engineers to maintain stable API contracts for a Vue.js application
- Contribute to and improve CI/CD pipelines (Azure DevOps)
- Apply sound algorithmic and performance reasoning when designing or refactoring solutions
- Work closely with the wider engineering team in a structured, quality‑focused development environment
Mandatory Technical Skills
- Strong C# and modern .NET experience
- Collections and data structures
- Asynchronous and parallel programming
- LINQ
- Strong ASP.NET experience
- Hands‑on Entity Framework Core knowledge
- Migrations
- Transactions
- Writing performant queries
- Proven ability to debug and work effectively in large legacy codebases
- Microsoft SQL Server experience
- Writing performant SQL
- Investigating and resolving database issues
- Experience working with CI/CD pipelines (e.g. Azure DevOps)
- Solid theoretical understanding of algorithms and performance
- Runtime and space complexity
- Designing efficient, scalable solutions
Strong Plus / Nice to Have
- Previous experience with ASP.NET Boilerplate (ABP) and successful migration away from it
- Basic experience with Vue.js
- Understanding API contracts
- OpenAPI / Swagger integration
- Exposure to TypeScript
FAQs
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