Principal Engineer (.NET/AWS)

Principal Engineer (.NET/AWS) - 12 Month Contract

Up to £650/day Outside IR35
Manchester (2 days onsite)/Hybrid

We're working with a large UK technology platform undergoing a significant transformation, rebuilding its core systems into a modern, cloud-native architecture.

This is a principal-level role at the centre of a full platform re-architecture, offering real ownership and influence across a high-profile programme.

The Project

• Migrating Legacy systems into AWS-based microservices
• Delivering a next-generation digital platform supporting Real Time operations
• Using a strangler pattern approach to modernise without disruption
• Building event-driven systems and Real Time data capabilities

The Role

You'll operate as a hands-on Principal Engineer, combining technical leadership with delivery:

• Take ownership of architecture and engineering direction across key services
• Design and build scalable, cloud-native .NET solutions in AWS
• Drive adoption of modern patterns (microservices, event-driven, domain-led design)
• Influence engineering standards, tooling, and best practice across teams
• Work closely with product, architecture, data and platform teams on complex, business-critical systems
• Play a key role in shaping AI-assisted development practices and modern ways of working
• Mentor engineers and raise the technical bar across the function

What makes this role stand out:

• Genuine principal-level ownership, not just delivery
• A large-scale, complex transformation rather than incremental change
• Opportunity to influence architecture, tooling, and engineering culture
• Modern, well-defined tech strategy with long-term investment
• A programme with longevity and strong extension potential

Tech Stack

• .NET 8/C#
• AWS (EKS, ECS, Lambda)
• Terraform
• Event-driven architecture (SNS/SQS, EventBridge)
• SQL & NoSQL (Aurora, DynamoDB)
• Docker/Linux
• CI/CD (GitHub Actions)

What They're Looking For

• Principal or Lead-level engineering experience
• Strong background in .NET and AWS
• Experience building scalable, distributed systems
• Proven track record in modern architecture and engineering leadership

This is a high-impact role within a long-term transformation programme, offering real influence over how a modern platform is built and scaled.

If this sounds relevant, apply or get in touch for a confidential conversation.