Fullstack Java Developer

Square One Resources; Leeds; On-site; GBP 40,000 - 70,000; Full time

Job summary

Square One Resources is seeking a Software Engineer in Leeds to design, build and evolve backend services and APIs, with a strong emphasis on reliability and integration.

The contract is initially 2 months and onsite every Tuesday and Thursday. The role offers a competitive salary between £40,000 and £70,000 per year, with potential extension and conversion to permanent as the project progresses.

Qualifications

• Strong backend engineering experience; Java is preferred, but we welcome engineers with strong experience in comparable object-oriented languages.
• Experience delivering solutions that span backend and frontend technologies, with a solid understanding of how systems fit together end to end.
• Demonstrated technical leadership through influencing engineering decisions, driving initiatives, and supporting the success of others.
• A strong quality-first mindset, including experience with automated testing, code reviews, and maintainable software design.
• Strong problem-solving, communication, and collaboration skills.
• Openness to adopting modern engineering practices, including AI-assisted development and spec-driven approaches.

Responsibilities

• Design, build, test, and deliver features across the stack, with a strong emphasis on backend services and APIs.
• Contribute to architectural decisions and technical strategy, helping shape the long-term direction of our products and platforms.
• Leverage AI-assisted development tools and spec-driven engineering practices to improve productivity, code quality, and delivery effectiveness.
• Champion engineering excellence through automated testing, code reviews, observability, maintainability, and continuous improvement.
• Collaborate closely with product managers, designers, QA engineers, and fellow developers to solve complex customer problems.
• Support and mentor other engineers through knowledge sharing, technical guidance, and constructive feedback.
• Participate in the continuous improvement of engineering processes, tooling, and delivery practices.

Skills

Backend engineering

Java

Frontend integration

Technical leadership

Automated testing

Code reviews

Maintainable design

AI-assisted development

Systems thinking

Tools

Java

Job description

Salary: £40,000 - 70,000 per year

Requirements:

• Strong backend engineering experience; Java is preferred, but we welcome engineers with strong experience in comparable object-oriented languages.


• Experience delivering solutions that span backend and frontend technologies, with a solid understanding of how systems fit together end to end.


• Demonstrated technical leadership through influencing engineering decisions, driving initiatives, and supporting the success of others.


• A strong quality-first mindset, including experience with automated testing, code reviews, and maintainable software design.


• Strong problem-solving, communication, and collaboration skills.


• Openness to adopting modern engineering practices, including AI-assisted development and spec-driven approaches.

Responsibilities:

• Design, build, test, and deliver features across the stack, with a strong emphasis on backend services and APIs.


• Contribute to architectural decisions and technical strategy, helping shape the long-term direction of our products and platforms.


• Leverage AI-assisted development tools and spec-driven engineering practices to improve productivity, code quality, and delivery effectiveness.


• Champion engineering excellence through automated testing, code reviews, observability, maintainability, and continuous improvement.


• Collaborate closely with product managers, designers, QA engineers, and fellow developers to solve complex customer problems.


• Support and mentor other engineers through knowledge sharing, technical guidance, and constructive feedback.


• Participate in the continuous improvement of engineering processes, tooling, and delivery practices.

Technologies:

• AI


• Backend


• Frontend


• Support


• Java


• Fullstack

More:

We have an exciting opportunity with one of our enterprise data analytics clients for an initial 2 month contract, with a likelihood of extension and conversion to permanent. The role is based in Leeds and requires onsite work every Tuesday and Thursday. The salary/rate is up to £600 daily inside IR35, and the start date is within the next two weeks. We are looking for a Software Engineer to help design, build, and evolve products from concept to production, working closely with product, design, and QA to deliver high-quality solutions that solve real user problems.

last updated 37 week of 2026