Senior .Net Engineer | C#, .NET | Application, Migration & Rebuild

• Day Rate: £450-£550 per day (Outside IR35)
• Remote: company meets at most 1 day per month in their Cambridge Office

The Role

You’ll join a major rebuild programme within a global specialist logistics organisation supporting the scientific and R&D community. This is a project-based contract focused on modernising a long-standing operational monolith covering transport management, warehousing, supplier workflows, manufacturing operations, and end-to-end shipment tracking.

Working closely with a BA and operational stakeholders, you’ll define requirements, analyse workflows, understand database structures and transform complex legacy components into clean, well-designed, well-documented modules. Expect a workload split of 50% design, 25% coding, and 25% testing, with a strong emphasis on consultation, documentation and knowledge transfer to internal developers.

You’ll operate in a regulated, precision-driven environment where reliability, clarity and thoughtful engineering matter.

Non-Negotiables

• C# .NET experience (minimum 3–5 years)
• Legacy system experience; large monoliths, tightly coupled modules, and untangling complex flows
• SQL Server expertise: stored procedures, schema interpretation, optimisation
• Ability to work safely with under-tested or untested codebases
• Strong stakeholder communication and requirements-gathering capability
• Ability to produce high-quality documentation, diagrams and structured module designs

Nice to Haves

• Experience modernising monolithic architectures into modular or service-based designs
• Blazor experience (or willingness to adopt it as the primary UI framework)
• Characterisation testing experience for documenting existing behaviour
• Exposure to logistics, manufacturing, supply chain or inventory systems
• Familiarity with regulated or compliance-heavy technical environments

What You’ll Work With

• C#/.NET (.NET Framework 4.0 → .NET 8)
• Blazor (core future direction) and limited Angular exposure
• SQL Server databases + stored procedures
• Entity Framework Core (migration from ADO / stored procedure-heavy patterns)
• Internal APIs spanning customer, inventory, transport and reporting modules
• Data flows feeding a centralised data warehouse
• Introduction of robust unit testing for previously under-tested components
• On-prem applications hosted on SAN due to regulatory requirements

Why Join

You’ll play a key role in a strategic, organisation-wide platform rebuild. You’ll help untangle a complex ecosystem of legacy modules, define clearer architectural boundaries, shape requirements and introduce modern .NET practices. Your work will directly support the delivery of high-precision logistics technology used globally by scientific organisations that depend on accuracy, compliance and reliability. This is a chance to influence architectural direction while working on mission-critical systems that genuinely matter.

Senior .Net Engineer | C#, .NET | Application, Migration & Rebuild