Senior AI Engineer

MRJ Recruitment Limited; Manchester; On-site; GBP 70,000 - 110,000; Full time

Job summary

MRJ Recruitment Limited seeks a Senior Software Engineer (AI First) to help modernise a major enterprise application in the UK. You will shape AI-assisted software development, productionise PoCs, and drive cloud migration with Azure.

You’ll collaborate with technical leaders to design APIs, build scalable back-end services, and establish repeatable patterns across transformation initiatives. Strong Azure and MS stack experience is essential.

Qualifications

• Proven experience delivering complex application modernisation projects as Senior Software Engineer, Technical Lead or Principal Engineer.
• Strong Azure cloud experience including migration/modernisation.
• Experience designing and building APIs and service-based architectures.
• Extensive backend development experience, ideally within the Microsoft technology stack.

Responsibilities

• Utilise AI-assisted development tools to accelerate analysis, refactoring and modernisation of a legacy application.
• Productionise an existing proof of concept into secure, scalable backend services.
• Design and develop APIs and middle-tier services for external integration.
• Work with evolving database structures to support the modernised application.
• Produce technical documentation, automated tests and deployment artefacts.
• Collaborate to establish secure, maintainable AI-assisted software engineering practices.
• Contribute to Azure migration activities within the broader programme.
• Define engineering approaches transferable to future transformations.

Skills

AI-first development

Azure cloud

API design

Backend development (Microsoft stack)

CI/CD

Software architecture

Tools

Codex

GitHub Copilot

Cursor

Claude Code

Job description

We have a brilliant opportunity for a Senior Software Engineer (AI First) to help shape the future of AI-assisted software development within a major application modernisation programme.

What's the role?

Following a successful in-house proof of concept, we're looking for an experienced Senior Software Engineer to help productionise an AI-assisted development approach using tools such as Codex and Claude, accelerating the modernisation of one of our core internally developed applications.

Working closely with technical leaders and engineering teams, you'll play a key role in transforming a legacy monolithic application into a modern, cloud-ready solution. You'll use AI-assisted development techniques to accelerate analysis, refactoring and engineering delivery, while helping establish a repeatable approach that can be adopted across future application modernisation programmes.

This engagement will support the first stage of a wider transformation programme focused on modernising the application and migrating it to Azure, with the potential for further work as additional capabilities are introduced.

If you're passionate about modern software engineering, enjoy solving complex technical challenges, and are excited by the opportunity to combine AI-assisted development with enterprise-scale modernisation, we'd love to hear from you.

Key Responsibilities

• Utilise AI-assisted development tools, including Codex, Claude and Cursor to accelerate the analysis, refactoring and modernisation of a legacy monolithic application.
• Productionise an existing proof of concept into secure, scalable and maintainable backend services aligned with the target architecture.
• Design and develop APIs and middle-tier services to support integration with an external React development partner.
• Work with existing and evolving database structures to support the modernised application.
• Produce technical documentation, automated testing and deployment artefacts to support migration, testing and production release.
• Collaborate with engineering teams to establish secure, maintainable and repeatable AI-assisted software engineering practices.
• Contribute to Azure migration activities as part of the wider application modernisation programme.
• Help define an engineering approach that can be leveraged across future technology transformation initiatives.

Person Requirements

• Proven experience as a Senior Software Engineer, Technical Lead or Principal Engineer delivering complex application modernisation projects.
• Strong experience modernising legacy or monolithic enterprise applications.
• Extensive backend development experience, ideally within the Microsoft technology stack.
• Experience designing and building APIs and service-based architectures.
• Strong Azure cloud experience, including application migration and modernisation.
• Experience working with complex relational databases and evolving data models.
• Practical experience using AI-assisted development tools such as Codex, GitHub Copilot, Cursor, Claude Code or similar within a commercial software engineering environment.
• Strong understanding of software engineering best practices, automated testing, CI/CD and secure application development.
• Excellent communication skills with the ability to collaborate effectively across engineering and business teams.

Next Steps

We're looking for an engineer who can combine deep technical expertise with modern AI-assisted development practices to accelerate enterprise application modernisation. If you're excited by the opportunity to shape how AI is used in software engineering whilst delivering tangible business outcomes, we'd love to hear from you.