Senior Java Engineer – AI & Modernisation

Myn; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

Myn is seeking a Senior Java Engineer in London for AI-enabled modernisation of large-scale platforms. You will work on modernising backend services, moving legacy applications to microservices and APIs, and exploring AI-assisted development to improve code analysis, testing, and automation.

You’ll build AI-enabled workflows and demonstrate safe deployment in a production environment. Hybrid pattern in London with strong Java ownership required.

Qualifications

• Extensive Java backend engineering experience.
• Spring Boot, APIs and microservices experience.
• Experience modernising complex production applications.
• Knowledge of distributed systems and service-based architectures.
• CI/CD and automated testing experience.
• Cloud-based application development experience.
• Strong software design and engineering fundamentals.
• Experience working with business-critical production systems.

Responsibilities

• Modernise complex backend services and move legacy apps to clean APIs and microservices.
• Leverage AI/LLMs to improve code analysis, refactoring, testing and automation.
• Develop reusable AI-enabled engineering workflows for production environments.
• Demonstrate safe and effective AI usage within large-scale systems.

Skills

Java backend

Spring Boot

APIs & microservices

Distributed systems

CI/CD

Cloud development

Software fundamentals

Production systems

Tools

Claude Code

GitHub Copilot

Cursor

LLM APIs

Model Context Protocol (MCP)

Agentic AI workflows

Job description

Senior Java Engineer – AI & Modernisation

London | Hybrid

Myn is recruiting for a major financial technology organisation investing heavily in the use of AI across software engineering and the modernisation of large-scale technology platforms.

The role

You’ll work on the modernisation of complex backend services, helping move legacy applications towards cleaner APIs, microservices and modern cloud-based architectures.

Alongside hands‑on Java engineering, you’ll explore how LLMs and AI‑assisted development can improve code analysis, refactoring, testing, documentation and delivery automation.

You’ll have the opportunity to build reusable AI‑enabled engineering workflows and help demonstrate how these tools can be applied safely and effectively within a large production environment.

What we’re looking for

• Extensive Java backend engineering experience
• Spring Boot, APIs and microservices
• Experience modernising complex production applications
• Distributed systems and service‑based architectures
• CI/CD and automated testing
• Cloud‑based application development
• Strong software design and engineering fundamentals
• Experience working with business‑critical production systems

We’re particularly interested in practical experience with some of the following

• Claude Code, GitHub Copilot, Cursor or similar AI development tools
• LLM APIs and AI integrations
• Model Context Protocol (MCP)
• Agentic AI workflows
• AI‑assisted code analysis and refactoring
• Automated test and documentation generation
• AI‑enabled CI/CD and engineering automation
• Prompt engineering and understanding the capabilities and limitations of LLMs

You don’t need to tick every AI box. What’s important is that you’re already experimenting with or implementing AI as an engineering tool rather than simply having an interest in the subject.

Location: London
Working pattern: Hybrid

If you’re a strong Java Engineer who wants to be at the forefront of how AI is changing software engineering, this could be an excellent next move.