Fullstack Java Developer - Leeds

Square One Resources; Leeds; On-site; GBP 66,000 - 111,000; Full time

Job summary

Square One Resources is seeking a Fullstack Java Developer to join our client in Leeds for an initial 3-month contract, with the possibility of extension and permanent conversion. The role requires on-site presence in Leeds two days a week (Tuesdays and Thursdays).

The assignment pays up to £600 daily inside IR35 and starts within two weeks, with a strong focus on backend engineering and scalable architectures.

Qualifications

• Strong backend engineering experience with Java or equivalent OO languages.
• Experience delivering backend and frontend solutions and understanding system integration."
• Proven ability to influence engineering decisions and mentor teammates.
• Quality-first mindset with automated testing, code reviews and maintainable design.

Responsibilities

• Design, build, test, and deliver features across the stack with emphasis on backend services and APIs.
• Contribute to architectural decisions and technical strategy for long-term product direction.
• Leverage AI-assisted tools and spec-driven practices to improve productivity and quality.
• Champion engineering excellence through testing, observability, and continuous improvement.
• Collaborate with product managers, designers, QA engineers, and other developers to solve complex problems.
• Mentor other engineers through knowledge sharing and feedback.
• Participate in improving engineering processes, tooling, and delivery practices.

Skills

Java

Backend engineering

API design

Code reviews

Automated testing

Observability

AI-assisted development

Leadership

Job description

Job Title: Fullstack Java Developer - Leeds
Location: Leeds 2x a week - Tuesdays and Thursdays
Salary/Rate: Up to £600 daily Inside IR35
Start Date: In the next two weeks
Job Type: Initial 3 month contract with likelihood to be extended and converted to perm

*Candidates applying must be able to work on site to Leeds every Tuesday and Thursday.

Company Introduction

We have an exciting opportunity now available with one of our enterprise data analytics clients. They are currently looking for a skilled Java Developer to join their team for an initial 3-month contract.

We're looking for a Software Engineer to help design, build, and evolve products from concept to production. You'll contribute across the technology stack with a strong focus on backend engineering, working closely with product, design, and QA to deliver high-quality solutions that solve real user problems.

Job 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.

Essential:

• 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.

Disclaimer
Notwithstanding any guidelines given to level of experience sought, we will consider candidates from outside this range if they can demonstrate the necessary competencies.
Square One is acting as both an employment agency and an employment business, and is an equal opportunities recruitment business. Square One embraces diversity and will treat everyone equally. Please see our website for our full diversity statement.