Java Principal / Lead engineer – Java, AWS, MongoDB, Architecture, design - UK remote, Outside contract
2 month initial plus extension
We are working with a business who are rebuilding their core platform from the ground up and are looking for a Lead Java engineer who’s up for a real challenge.
 
Their system was originally built externally, and they've now brought it fully in-house. So, your mission is to get under the hood, untangle what’s there, and help them design something better — cleaner, faster, and built to scale. Someone with a forensic mind who is then able to get on with the fix. You will understand the architecture and be able to unpin what they have to design and build a better solution
 
You’ll work with the Tech Manager, Product Owner, and Solution Architect to modernise the platform and shape the next generation of features.
 
What You’ll Be Doing 

• Own the project entirely, end to end — from discovery and design to delivery and optimisation. 
• Work across the stack using Java, React, AWS, MongoDB, and Elasticsearch. 
• Refactor and re-engineer core components to make the platform faster, more reliable, and easier to extend. 
• Collaborate closely with product and architecture teams. 
• Review code, mentor teammates, and bring fresh thinking to the table. 
• Write clean, well-documented code that’s built to last. 

Experience 

• Strong experience within the Java AWS stack 
• Experience modernising or replatforming legacy systems. 
• Familiarity with microservices, CI/CD, or serverless architectures. 
• An interest in building scalable, high-performing distributed systems.
• A great understanding of modern software architecture, design principles and data structures. 
• Practical experience with Java, React, MongoDB and AWS 
• Curiosity and persistence — you enjoy cracking tough problems and simplifying complexity. 
• The ability to balance autonomy with collaboration

 
If this sounds like you then let me know and we can set up a call.

2 stage interview process completed in the next 2 weeks and immediate start thereafter