Contract - Senior/Principal Java Developer

Source Technology; London; On-site; GBP 95,000 - 110,000; Full time

Job summary

A leading financial institution is seeking a Principal Java Developer to modernize legacy systems and deliver new functionalities. This hands-on role involves collaboration with infrastructure, architecture, and infosec teams, focusing on backend development while leading CI/CD initiatives and designing REST APIs.

Qualifications

• Proven experience supporting large-scale, business-critical systems.
• Strong background in Java and ideally C#.
• Comfortable working with legacy systems and large enterprise environments.

Responsibilities

• Lead critical systems work within a high-performing team.
• Guide CI/CD improvements and support high-availability production systems.
• Collaborate on technical conversations across multiple engineering disciplines.

Skills

Java

C#

CI/CD

REST API Design

Angular

React

SQL

Job description

This range is provided by Source Technology. Your actual pay will be based on your skills and experience — talk with your recruiter to learn more.

Base pay range

Direct message the job poster from Source Technology

Manager - UK&I at SGI, organiser of Source Talks: On Kotlin

We’re working with a major financial institution looking to scale out its engineering function with a Principal Java Developer to lead critical systems work. This is a hands-on role within a high-performing team modernising legacy platforms, improving availability, and delivering new functionality across the estate.

You’ll be working closely with infrastructure, architecture, and infosec teams to support high-availability production systems. The role also involves guiding CI/CD improvements, REST API design, and steering collaborative technical decisions across squads.

What they’re looking for:

• Proven experience supporting large-scale, business-critical systems
• Strong background in Java and ideally C#
• Some front end exposure (Angular ideally but other frameworks considered). Note the role is back end focused.
• Comfortable working with legacy systems and large enterprise environments
• Confident leading technical conversations across multiple engineering disciplines
• Experience with CI/CD pipelines and modern deployment practices
• Greenfield REST API design including HATEOAS implementation
• Angular, React or frontend exposure
• Familiarity with Snowflake or backend SQL variants

This is a great opportunity for an experienced Java Developer to join a prestigious financial player. If you’re someone who thrives in complex environments and enjoys technical leadership alongside delivery, apply now.

Seniority level

• Seniority level

  Mid-Senior level

Employment type

• Employment type

  Full-time

Job function

• Job function

  Information Technology

• Industries

  Software Development and Financial Services

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