1,065 Back End Developer jobs in the United Kingdom

Senior Backend Developer- Node.JS

Express new ideas, take initiative and save lives. Others talk about being brave, at CLEO Systems, we’re made that way.

By providing highly capable, innovative, and integrated software solutions within integrated urgent care – every role at CLEO Systems is made to be brave.

As a Senior Software Developer at Cleo Systems, you will play a key role in designing, building, and maintaining robust, high-performance backend services that power our healthcare applications. You’ll work with modern technologies including Node.js, Redis, RabbitMQ, Postgres, and Docker to deliver scalable and secure software that directly supports clinicians and patients.

You will take ownership of critical technical components, contribute to architecture decisions, and collaborate with cross-functional teams including DevOps, Product and QA to ensure high-quality delivery. Your experience in event-driven systems, microservices, and containerised environments will help shape our evolving platform.

The ideal candidate for this role would be an experienced engineer who enjoys solving complex problems, writing clean and efficient code, and mentoring others to uphold best practices in software engineering.

You will have experience with –

• Backend Development: Design, develop, and maintain backend services using Node.JS
• Messaging & Asynchronous Workflows: Build and manage reliable messaging patterns using queues such as RabbitMQ and Pub/Sub patterns.
• Database Design: Develop efficient and scalable queries and schemas using PostgreSQL.
• API Design: Develop clean, RESTful APIs and contribute to internal and external API documentation.
• Containerisation: Aid in building services in containerised environments using Docker.
• Code Quality: Write testable, maintainable code and contribute to peer reviews, testing, and CI/CD pipelines.

Who are we?

CLEO Systems is a wholly owned subsidiary of Integrated Care 24 (IC24), the leading not-for-profit Social Enterprise providing innovative, and patient focused primary care services. We are committed to delivering ‘Clinical Excellence Online’ (CLEO). Through this mission we contribute to the wider Group ambition to improve access to health and social care for patients and reduce the demand on secondary care services. IC24 provides services to over 6 million patients, including GP led out-of-hours services, NHS 111, primary care and secondary care support services.

Location Hybrid (occasional travel to Ashford Kent)

Hours 37.5 per week

What’s in It for You?

• Salary : £70,000 per annum, depending on experience
• Location: Hybrid – Remote & occasional travel to our office in Ashford, Kent
• Benefits : Access to the Nest Company Pension Scheme, free 24/7 independent counselling service, and a reward and discount platform.
• Benenden Health : company paid health support from private GP appointments to secondary care treatment.
• Learning and Development : Opportunities to advance your career through training and development.
• Community Engagement : We support volunteering and provide one paid day annually for community or charitable activities.

Due to the nature of this position, employment is subject to proof of eligibility to work in the UK, completion of a satisfactory basic DBS disclosure and two references.

Closing date: 23rd September 2025

At CLEO Systems we celebrate brave ideas and brave people.

We are committed to providing equal opportunities for all people and we particularly encourage applications from ethnic minorities, applicants with a disability and those from other under-represented groups.

If you would like to discuss any reasonable adjustments before applying or would like an accessible version of any recruitment documents, please contact the recruitment team on

We're on the lookout for a Java Developer with commercial Java experience (12 months will suffice)

Based in Sheffield City Centre, we have placed the majority of Developers within the business since 2008 - many of whom have gone onto become Senior Engineers.

A minimum of post-degree experience of 1 year is required for this post.

Role Overview

• Development of backend web applications using Java to deliver support for existing systems and to develop new functionality across projects.
• You will work within agile teams across projects to learn and upskill in multiple technologies.
• Alongside this you will take on responsibilities for backend testing and automation, working closely with the Technical Architect with a view to unifying standards across backend projects.

Essential Experience

• A minimum of one year working in industry using:
  • Java language
  • Relational databases

Desired Experience:

• Java development (Spring Boot or otherwise)
• SQL, Postgres
• Integration testing practices and languages
• Devops procedures

You will be:

• A logical thinker
• A natural problem solver, able to research and investigate issues in a self-directed manner
• Keen to apply high professional standards and take pride in your work
• A pro-active and effective team member
• A good communicator
• Very open to knowledge sharing and learning

Please send your CV to express interest.

Calibre Search promote equality in the workplace and we welcome applications from all suitably skilled or qualified candidates regardless of their sex, race, disability, religion/beliefs, sexual orientation or age. We act as both an employment agency and employment business.

Backend Developer – Early Employee Opportunity

We’re a fast-growing, funded startup building the next generation of data-driven platforms. As one of our early employees , you’ll join a small, multidisciplinary team working closely with the leadership team on the migration of our platform from v0 → v1 and the development of new features. This role offers a clear path to grow into a senior developer or product owner as the company scales.

What you’ll do:

• Build and expand backend applications using Python (FastAPI)
• Design and implement microservices and REST APIs
• Write clear documentation, unit tests, and end-to-end tests
• Work with AWS, Docker, SQLAlchemy, and SQL databases
• Deploy features via CI/CD workflows into production
• Contribute to architecture for local and cloud deployment

What we’re looking for:

• Strong skills in Python (3.11+) and OOP principles
• Experience with cloud architecture (AWS) and containerization
• Hands-on knowledge of SQL databases and ORM frameworks
• Familiarity with Agile workflows, GitHub, Jira, and modern CI/CD practices
• A problem-solver who thrives in dynamic, fast-paced environments

Why join us?

️ Be part of a profitable, scaling startup with exciting growth plans

️ Work directly with the leadership team on high-impact projects

️ Hybrid role – South England / London , with 2 days a week in a co-working space

️ Benefits include private medical insurance, pension, and 22 days holiday + bank holidays

Backend Developer – Early Employee Opportunity

We’re a fast-growing, funded startup building the next generation of data-driven platforms. As one of our early employees , you’ll join a small, multidisciplinary team working closely with the leadership team on the migration of our platform from v0 → v1 and the development of new features. This role offers a clear path to grow into a senior developer or product owner as the company scales.

What you’ll do:

• Build and expand backend applications using Python (FastAPI)
• Design and implement microservices and REST APIs
• Write clear documentation, unit tests, and end-to-end tests
• Work with AWS, Docker, SQLAlchemy, and SQL databases
• Deploy features via CI/CD workflows into production
• Contribute to architecture for local and cloud deployment

What we’re looking for:

• Strong skills in Python (3.11+) and OOP principles
• Experience with cloud architecture (AWS) and containerization
• Hands-on knowledge of SQL databases and ORM frameworks
• Familiarity with Agile workflows, GitHub, Jira, and modern CI/CD practices
• A problem-solver who thrives in dynamic, fast-paced environments

Why join us?

️ Be part of a profitable, scaling startup with exciting growth plans

️ Work directly with the leadership team on high-impact projects

️ Hybrid role – South England / London , with 2 days a week in a co-working space

️ Benefits include private medical insurance, pension, and 22 days holiday + bank holidays

We're on the lookout for a Java Developer with commercial Java experience (12 months will suffice)

Based in Sheffield City Centre, we have placed the majority of Developers within the business since 2008 - many of whom have gone onto become Senior Engineers.

A minimum of post-degree experience of 1 year is required for this post.

Role Overview

• Development of backend web applications using Java to deli.

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