Talent.com
RE Partners
Principal Full-Stack Engineer (Java,React,LLMs)RE Partners • Southampton, UK
Principal Full-Stack Engineer (Java,React,LLMs)

Principal Full-Stack Engineer (Java,React,LLMs)

RE Partners • Southampton, UK
4 days ago
Job type
  • Full-time
Job description

We’re hiring a Principal Full-Stack Engineer to join one of the largest banking institutions in the U.S. - a highly complex, high-impact environment where engineering decisions truly matter.

This role is ideal for someone who combines deep backend expertise in Java with strong frontend capabilities in React, and hands-on experience working with LLMs (Claude preferred).


What you’ll be doing:

  • Lead the design and development of scalable backend services in Java (Spring Boot)
  • Build and optimize secure, high-performance APIs
  • Contribute to and guide React-based frontend architecture
  • Work hands-on with LLM/AI technologies (Claude or similar), integrating them into real-world applications
  • Drive best practices across code quality, architecture, and performance
  • Mentor engineers and support UI developers in delivering high-quality solutions
  • Partner with stakeholders to translate business needs into technical execution
  • Contribute to system design discussions, code reviews, and continuous improvement


What we’re looking for:

  • Strong experience in Java backend development and server-side architecture
  • Solid React experience on the frontend
  • Hands-on experience with LLMs / AI tools and practical implementation
  • Experience designing and building scalable, distributed systems
  • Strong understanding of APIs, databases, and performance optimization
  • Proven ability to lead technically and mentor others


Nice to have:

  • Experience with GraphDB, Scala, or complex data processing systems
  • Exposure to cloud platforms (AWS, Azure, or GCP)
  • Familiarity with CI/CD pipelines and DevOps practices


Why join us?

At RE Partners, we partner with industry leaders to deliver high-impact technology solutions. We’re not a traditional staffing agency - we operate as a true consulting partner, helping organizations navigate complex digital transformations. Our global team, diverse culture, and strong delivery model have made us a trusted partner to Fortune 1000 companies.

If you’re excited about building at scale, working with cutting-edge AI, and operating at a principal level - let’s connect.

Create a job alert for this search

Principal Full-Stack Engineer (Java,React,LLMs) • Southampton, UK

Similar jobs

Full-Stack.NET Engineer – Hybrid, Impactful Tech

Vodafone Group PlcNewbury, England, United Kingdom
Full-time

A leading telecommunications company in Newbury is seeking a skilled.NET Developer to join their Technology team.This role involves full-stack development, focusing on building and maintaining.NET ... Show more

 • Promoted

Principal Engineer

hackajobSouthampton, England, United Kingdom
Full-time

We’re looking for an exceptional Principal Engineer to operate as a senior technical authority within Business Systems.You’ll provide deep technical expertise, lead on our most complex engineering ... Show more

 • Promoted

Principal Systems Engineer

TieTalentCowes, England, United Kingdom
Part-time

Location: Isle of Wight – Cowes; Chelmsford – Great Baddow; Portsmouth – BroadOak; and other sites as applicable.Salary: Up to £75,900 commensurate with skills and experience.Part-time options avai... Show more

 • Promoted

Staff Engineer & Team Lead - Backend & Architecture

Starling Bank LimitedSouthampton, England, GB
Full-time

A leading fintech company is seeking a Staff Engineer to lead and inspire engineering teams at their London office.The role includes coaching team members, overseeing complex projects, and contribu... Show more

 • Promoted

Principal Systems Engineer

Sirius Analysis LimitedSouthampton, United Kingdom
Full-time

Role:Principal Consultant - Systems Engineering.Sirius Analysis, we are a rapidly growing consultancy firm, renowned for our reputation and our keen ability to understand and meet customer requirem... Show more

 • Promoted

Innovations Software Engineer — Full-Stack & Automation

TÜV SÜDFareham, England, United Kingdom
Full-time

A leading technology solutions provider is looking for an Innovations Engineer in Fareham, UK.This role involves maintaining and developing software solutions to enhance internal processes within a... Show more

 • Promoted

Platform Engineer - Engine by Starling

StarlingSouthampton, England, United Kingdom
Full-time

At Engine by Starling, we are on a mission to find and work with leading banks worldwide who have the ambition to build rapid‑growth businesses using our technology.We have a hybrid approach to wor... Show more

 • Promoted

Software Engineering Manager

Yoh, A Day & Zimmermann CompanySouthampton, ENG, GB
Permanent +1

This isn’t a role for someone who wants to stay hands-on in the code.It’s for someone who knows how high-performance software gets built — and wants to lead the people and environ... Show more

 • Promoted • New!

Full-Stack Engineer for Scientific Imaging & Real-Time UI

Innovative PhysicsShanklin, England, GB
Full-time

Innovative Physics in Shanklin is looking for a Full Stack Developer with a strong scientific background.The position requires expertise in designing intuitive web interfaces for scientific applica... Show more

 • Promoted • New!

Senior Full Stack Engineer Engineering Southampton, UK

KaleidoSouthampton, England, United Kingdom
Full-time

Kaleido is the leading enterprise-grade Web3 platform for blockchain and digital assets in the world.Its full-stack infrastructure includes access to all major protocols and chains, 500+ pre-built ... Show more

 • Promoted

Cloud-Native Full-Stack Engineer | Microservices & APIs

IBMWinchester, England, GB
Full-time

A leading technology firm in the United Kingdom is seeking a Full Stack Developer to develop cloud-native, end-to-end applications for various clients.The role involves working with modern front-en... Show more

 • Promoted

Principal Software Engineer

Synergize ConsultingSouthampton, England, UK
Full-time

We are looking for a ‘bare metal’ embedded software engineer to join our clients team developing the next generation of airborne integrated communication system for the Global Combat Air Programme ... Show more

 • Promoted

Junior Software Engineer (Java, AWS) – Scale BSS/OSS

Gamma Recruitment TeamNewbury, England, United Kingdom
Full-time

A leading technology firm in Newbury seeks a motivated Software Engineer to enhance systems within the BSS/OSS domain.The role involves designing high-quality code, reviewing performance and best p... Show more

 • Promoted

Full Stack Developer

SkyBound RescuerSouthampton, England, United Kingdom
Full-time

Get AI-powered advice on this job and more exclusive features.Are you a talented Full-Stack Developer passionate about innovative technology and making a difference? Join SkyBound, a funded startup... Show more

 • Promoted

Principal Design Engineer

NPA WorldWideSOUTHAMPTON, England, United Kingdom
Full-time +1

Location: Southampton hybrid, 3 days per week on-site.Salary: 65-85K plus excellent benefits package.A relocation package and Visa/Sponsorship support is available for this role if required.Our cl... Show more

 • Promoted

Senior Full-Stack Product Engineer

SimplyhealthSO21, ENG, GB
Full-time

Foundry is Simplyhealth’s venture incubator and strategic business development unit, investing millions into new healthcare businesses to accelerate the move towards predictive and preventati... Show more

 • Promoted • New!

Principal Software Engineer

Spectrum IT RecruitmentSouthampton, England, United Kingdom
Full-time

Principal Software Engineer – TypeScript, JavaScript, Angular, Linux, IoT, K8.Location: Southampton (Onsite).Salary: £75,000 + generous pension & benefits.Are you a Principal Engineer who thrives o... Show more

 • Promoted

Principal Software Engineer

Rocket Software, Inc.Newbury, England, United Kingdom
Full-time

It's fun to work in a company where people truly BELIEVE in what they're doing!****Job Description Summary:**The Infrastructure Modernization business unit is seeking a highly experienced Principal... Show more

 • Promoted

Principal Systems Engineer

BAE SystemsCowes, United Kingdom
Full-time

Isle of Wight – Cowes – 4/5 days weekly onsite.We offer a range of hybrid and flexible working arrangements – please.Up to £87,200 DOE + bonus scheme.Come and put yourself into a dynamic Principal... Show more

 • Promoted

Performance Engineer

Nautilus SearchSouthampton, England, UK
Full-time

The opportunity Our client is a fast-growing clean technology company at a pivotal stage of growth — first full-scale product installation complete, multiple commercial projects underway, and glob... Show more