Role Description

We are looking for a highly experienced, hands-on Lead .NET Modernization Engineer to lead the design and development of cloud-native modernization solutions within our Application Modernization practice. The ideal candidate has built deep, hands-on expertise in .NET Framework 4.x – whether early in their career or subsequently – and has since progressed to modern .NET (.NET 8 or later, targeting .NET 10 LTS). Designing and building migration tooling to support legacy application & data migration requires .NET 4.x framework-based development expertise and modernizing applications from .NET 4.x framework or any other frameworks to modern .Net requires expertise in .NET 8 or later. This role works alongside our established Enterprise Java modernization team and plays a key part in extending our modernization methodology and our spec-driven, AI-assisted development approach to .NET projects.

Key Responsibilities

• Lead the assessment of legacy applications including those developed using .NET Framework 4.x applications, defining modernisation avenues (re-platform, re-architect, re-write) and a target architecture on modern .NET (.NET 8 or later, targeting .NET 10 LTS).
• Design and develop cloud-native applications and services on modern .NET, targeting containerised deployment on OpenShift or hyperscaler Kubernetes stacks, consistent with our existing Java modernization architecture patterns.
• Lead and guide the design and development of bespoke migration tools and utilities that automate code analysis, transformation and data migration for large .NET modernization programmes.
• Apply spec-driven development practices using AI coding agents such as Microsoft Copilot, Claude Code and IBM Bob, adapting prompts and specifications to .NET migration and build activity.
• Contribute to discovery, requirement analysis and validation, design, build, testing, migration and go-live planning/execution, and stabilisation monitoring across the full modernization lifecycle.
• Design and develop integrations between modernised .NET services and back-office systems, databases and messaging platforms, ensuring performance, scalability and security.
• Establish coding standards, branching strategies and best practices for .NET modernization work, aligned with the practice’s existing Java modernization standards.
• Lead and mentor a team of .NET developers through design, build and testing, reviewing code and migration output for quality and adherence to target architecture.

Required Skills & Experience

Enterprise .NET Modernization Skills (Specialist)

• Deep, hands-on expertise in .NET Framework 4.x — built early in career or acquired over time — including strong command of its internals (CLR, IIS hosting, WCF, Web Forms/MVC, config-based deployment), essential to reliably analyse and reason about legacy .NET Framework 4.x codebases.
• Equally strong, hands-on expertise in modern .NET (.NET 8 or later, targeting .NET 10 LTS), including C#, ASP.NET Core, Entity Framework Core and modern cloud-native application patterns (minimal APIs, background services, dependency injection) – this combined depth across both eras of the platform is essential to the role, not an advantage.
• Proven experience leading and guiding the design and development of migration tools that bridge .NET Framework 4.x source codebases and modern .NET target architectures, including automated code analysis, transformation and data migration utilities – this is an essential, hands-on part of the role, not a peripheral one.
• Practical knowledge of common .NET modernization paths, such as moving from WCF, ASP.NET Web Forms/MVC and other .NET Framework 4.x technologies onto ASP.NET Core, gRPC/Web API and containerised services on modern .NET.

Cloud-Native & Platform Skills

• Hands-on experience building and deploying containerised .NET applications on OpenShift or hyperscaler Kubernetes stacks.
• Experience with Docker, CI/CD pipelines and infrastructure-as-code for .NET application delivery.
• Working knowledge of relational data stores such as SQL Server, PostgreSQL or MySQL, including schema and query migration considerations.

AI-Assisted & Spec-Driven Development Skills

• Working knowledge and hands-on experience of spec-driven development using AI coding agents such as Microsoft Copilot, Claude Code and IBM Bob, or equivalent tools.
• Ability to define clear specifications and prompts to guide AI coding agents through complex migration and build tasks, with sound judgement on where agentic assistance is and is not appropriate.

Leadership & Delivery Skills

• Proven experience leading and mentoring a team of developers through design, build and testing.
• Experience establishing coding standards and best practices for a development team and ensuring consistent adherence across projects.
• Ability to work closely with Solution Architects and cross-practice modernization teams to keep delivery aligned with the overall solution design and methodology.

Qualifications

• Bachelor’s degree in Computer Science, Software Engineering, Information Technology, or a related field.
• A minimum of 6-8 years of hands-on IT experience, with demonstrable, career-spanning depth in both .NET Framework 4.x and modern .NET (.NET 8 or later) — genuine expertise in both eras of the platform, not recent exposure to one layered on brief familiarity with the other.
• Microsoft certifications relevant to .NET development or Azure (e.g. Azure Developer Associate) will be a strong advantage.
• Certifications or training in containerisation, Kubernetes/OpenShift, or cloud platforms will be an advantage.
• Exposure to Generative AI or agentic coding tools, or training in spec-driven development practices, will be an advantage.
• Experience delivering modernization solutions for Banking and Financial Services or large enterprise customers is preferred.