18 senior backend developer jobs found

Senior Backend Developer (Java / Spring Boot / AWS) Rate: £500 - £600 Outside IR35 Location: London - 3 times on site a month Duration: 6 months initial The role: I'm working with a financial services organisation that needs a Senior Backend Developer to build and maintain cloud-based services on AWS. The work is hands-on and includes code reviews and input into technical decisions. Responsibilities: Build REST and event-driven microservices in Java and Spring Boot Deploy and support services on AWS (e.g. ECS/EKS, Lambda, RDS, DynamoDB, SQS/SNS) Own services from design through to production support Maintain CI/CD pipelines and infrastructure as code (Terraform, CloudFormation or CDK) Review code and contribute to architecture decisions Essential skills: Commercial experience with Java 21 and Spring Boot Building and running applications on AWS Microservices and API design Reasonable Adjustments: Respect and equality are core values to us. We...

Senior Backend Developer (Java/Spring Boot/AWS) Rate: £500 - £600 Outside IR35 Location: London - 3 times on site a month Duration: 6 months initial The role: I'm working with a financial services organisation that needs a Senior Backend Developer to build and maintain cloud-based services on AWS. The work is hands-on and includes code reviews and input into technical decisions. Responsibilities: Build REST and event-driven microservices in Java and Spring Boot Deploy and support services on AWS (eg ECS/EKS, Lambda, RDS, DynamoDB, SQS/SNS) Own services from design through to production support Maintain CI/CD pipelines and infrastructure as code (Terraform, CloudFormation or CDK) Review code and contribute to architecture decisions Essential skills: Commercial experience with Java 21 and Spring Boot Building and running applications on AWS Microservices and API design Reasonable Adjustments: Respect and equality are core values to us. We are...

Senior Backend Developer (Java / Spring Boot / AWS) Rate: £500 - £600 Outside IR35 Location: London - 3 times on site a month Duration: 6 months initial The role: I 'm working with a financial services organisation that needs a Senior Backend Developer to build and maintain cloud-based services on AWS. The work is hands-on and includes code reviews and input into technical decisions. Responsibilities: Build REST and event-driven microservices in Java and Spring Boot Deploy and support services on AWS (e.g. ECS/EKS, Lambda, RDS, DynamoDB, SQS/SNS) Own services from design through to production support Maintain CI/CD pipelines and infrastructure as code (Terraform, CloudFormation or CDK) Review code and contribute to architecture decisions Essential skills: Commercial experience with Java 21 and Spring Boot Building and running applications on AWS Microservices and API design...

Senior Backend Developer for Video on Demand and Live Streaming (GoLang) Contract 12 months OUTSIDE IR35 Remote (UK) A leading video platform is seeking experienced Senior Backend Developers with expertise in GoLang to contribute to the VoD2Live project. This person must have experience working on Streaming or Video on Demand click apply for full job details

Senior Backend Developer for Video on Demand and Live Streaming (GoLang) – Contract – 12 months – OUTSIDE IR35 – Remote (UK) A leading video platform is seeking experienced Senior Backend Developers with expertise in GoLang to contribute to the VoD2Live project. This person must have experience working on Streaming or Video on Demand. The role requires developing robust, high-performance backend services that integrate seamlessly with third-party services such as CDNs, DRM providers, and cloud platforms. This position is ideal for candidates with strong problem-solving skills and a deep understanding of video streaming protocols and microservices architecture. Key Responsibilities: · Develop functional and high-performing backend services that meet the platform's requirements. · Write high-quality, well-documented, and maintainable code. · Integrate the platform with necessary third-party services (CDNs, DRM providers, etc.). · Ensure comprehensive...

Staff Full Stack Engineer (Contract) | Rust & Java (Primary) | React & Python (Secondary) | Fully Remote (UK-based) | £500-600+/day | Outside IR35 | 12-Month Contract We’re partnering with a fast-scaling, globally distributed tech business that’s investing heavily in the evolution of its platform – modernising backend services, improving frontend experiences, and setting long-term architectural direction. They’re looking for a Staff Full Stack Engineer (Contract) with strong commercial experience in Rust and Java, alongside hands-on experience building production-grade applications with React and Python. This is a high-impact, long-term contract within an experienced, product-focused engineering team, where you'll play a key role in developing scalable backend systems, delivering modern frontend experiences, and influencing architectural decisions. It’s well suited to an experienced contractor who enjoys owning complex technical challenges, working...

🤖 Senior Android Engineer – Fintech - 6m OUTSIDE contract 💷 Up to £500/day | Outside IR35 📆 6-Month Contract 📍 Central London – 3 days onsite We’re working with a leading fintech scale-up looking for an experienced Senior Android Engineer to join their mobile engineering team on an initial 6-month contract. 📱 This is a highly product-focused role, working on a major Android product build and creating polished, data-rich mobile experiences. You’ll have genuine end-to-end ownership , from initial idea and technical approach through to testing and release. 👨 💻 A senior doer This is an important one: they need someone senior who is still very close to the code. They’re not looking for a hands-off Lead, they want a highly technical, hands-on Senior Android Engineer who can make good architectural decisions but still enjoys getting stuck into the implementation. You’ll also need to be a confident, clear communicator who can articulate your...

Scala QA Tester - 3 months+ - £300-350pd Outside IR35 - REMOTE UK We are looking for an experienced Scala QA Tester to support a long-term UK Government technology programme. Key Responsibilities Test Scala-based backend applications, APIs and microservices. Create and execute functional, integration, regression and end-to-end test cases. Develop and maintain automated testing frameworks and scripts. Identify, investigate and document defects. Work closely with Scala Developers and wider Agile delivery teams. Support CI/CD and continuous improvement of QA processes. Essential Skills & Experience Commercial experience in QA/Test Engineering. Experience testing Scala/JVM-based applications. Strong knowledge of API, microservices and backend testing. Experience with automated testing and CI/CD. Familiarity with ScalaTest, Playwright, Selenium, Cypress...

Scala QA Tester - 3 months+ - £300-350pd Outside IR35 - REMOTE UK We are looking for an experienced Scala QA Tester to support a long-term UK Government technology programme . Key Responsibilities Test Scala-based backend applications, APIs and microservices. Create and execute functional, integration, regression and end-to-end test cases. Develop and maintain automated testing frameworks and scripts. Identify, investigate and document defects. Work closely with Scala Developers and wider Agile delivery teams. Support CI/CD and continuous improvement of QA processes. Essential Skills & Experience Commercial experience in QA/Test Engineering . Experience testing Scala/JVM-based applications . Strong knowledge of API, microservices and backend testing . Experience with automated testing and CI/CD. Familiarity with ScalaTest, Playwright, Selenium, Cypress or similar . Experience with Git and Agile methodologies....

About the Company We're recruiting a Full Stack Developer for a software business. You'll join a small engineering team, working alongside the CTO on a new clinical-records product and an existing clinical transcription platform. About the Role Full Stack Developer | React, TypeScript & Node.js IR35: Outside IR35 Location: Glasgow, hybrid with two days per week onsite Duration: Initial six-month contract, with extension by agreement This is a mid-level role where you'll own features from requirement through to production, with code review and support from the team. The core stack is React, TypeScript, Node.js and PostgreSQL, with services deployed on Google Cloud and in containerised on-premise environments. Responsibilities Build features across React interfaces, TypeScript backend services and workers, and the database layer. Write and review SQL, data models, schemas and migrations for clinical and...

Full Stack Developer React, TypeScript & Node.js IR35: Outside IR35 Location: Glasgow, hybrid with two days per week onsite Duration: Initial six-month contract, with extension by agreement We're recruiting a Full Stack Developer for a software business. You'll join a small engineering team, working alongside the CTO on a new clinical-records product and an existing clinical transcription platform. This is a mid-level role where you'll own features from requirement through to production, with code review and support from the team. The core stack is React, TypeScript, Node.js and PostgreSQL, with services deployed on Google Cloud and in containerised on-premise environments. What you'll be doing Build features across React interfaces, TypeScript backend services and workers, and the database layer. Write and review SQL, data models, schemas and migrations for clinical and case data. Create unit, integration and end-to-end tests, and maintain working...

Full Stack Developer (React + Python/FastAPI) Healthcare Software Glasgow, Scotland (hybrid, 2 days a week in the office) | £350 375/day | 6-month contract, Outside IR35 | Start 20/10/2026 MindClon builds healthcare and medicolegal software that handles sensitive personal data under UK GDPR and clinical governance obligations. We're moving our clinical-records product off Firebase onto a new platform: a React front end, a Python/FastAPI API and background worker, PostgreSQL, and self-hosted language and speech models. The same containers run on Google Cloud and in on-premise installations with no Internet access. You'll build this platform with a small engineering team and the Chief Technical Officer. This is a mid-level role. You'll own features from requirement to production, with design review and support around you. What you'll do Build features end to end: React and TypeScript in the browser, and FastAPI endpoints with Pydantic validation, business logic and SQL...

Android Developer (Contract, Outside IR35) Contract status: Outside IR35 Start date: 2nd November Contract length: To the end of December 2026, with extension possible Location: Remote first London days: Once or twice a month Who you'll be doing it for You'll join the mobile platform team on a UK government app, working on the app and the services that support it. The team builds and maintains the common parts of the app, such as login. It also brings in key features built by other teams, and manages app releases. You're engaged through hedgehog lab, a digital product consultancy and certified B Corp, also Great Place to Work certified. For 20 years we've helped public and private sector organisations through digital transformation. What you'll be doing You'll build and improve the common parts of the Android app, such as login, in Kotlin with Jetpack Compose. You'll also work on how features built by other teams fit into the app. When your...

TypeScript Backend Developer (Contract, Outside IR35) Contract status: Outside IR35 Start date: 2nd November Contract length: To the end of December 2026, with extension possible Location: Remote first London days: Once or twice a month Who you'll be doing it for You'll join the mobile platform team on a UK government app, working on the app and the services that support it. The team builds and maintains the common parts of the app, such as login. It also brings in key features built by other teams, and manages app releases. You're engaged through hedgehog lab, a digital product consultancy and certified B Corp, also Great Place to Work certified. For 20 years we've helped public and private sector organisations through digital transformation. What you'll be doing You'll build the services behind the app, as TypeScript Lambda functions on AWS. You'll set up authentication using OIDC, so people can sign in securely. You'll agree with the...

Integration Software Engineer/(IPaaS - Boomi - AWS) - UK CNI - OUTSIDE IR35 - ACTIVE SC CLEARANCE NEEDED Tecknuovo is a deliberately different digital consultancy, delivering secure, modern technology solutions while upskilling client teams to ensure zero long-term dependency. We are seeking an experienced Integration Engineer, Software Engineer, Backend Engineer or Java Developer to support a high-profile integration Proof of Concept within a large-scale UK government organisation responsible for delivering critical national services. This role would suit engineers with a strong background in API development, Back End engineering, system integration or Middleware technologies , who enjoy solving complex technical challenges and building scalable solutions in cloud-based environments. You do not need to come from a pure Boomi background. Whilst experience with Boomi is highly desirable, we are equally interested in engineers who have delivered...

Contract Python Engineers – 3–6 Month Contracts London / Hybrid | £650–£750 pd Outside IR35 I’m working with a heavily VC-backed financial services platform that is going through a really exciting period of global expansion. They’ve built their own technology offering using modern Python and are disrupting a traditionally legacy-heavy sector. They’re now looking to bring in three technically strong Python Engineers on an initial 3–6 month contract, with the potential for further work. This is a small, highly technical team, so they’re looking for engineers who can genuinely stand on their own two feet. You’ll be expected to work across the development lifecycle rather than relying on someone else to handle areas such as testing, architecture or data structures. They’d particularly like to speak with people who have worked in smaller engineering teams, start-ups or scale-ups, where you’ve had to take ownership rather than being one small part of a huge...

Lead Java Software Engineer (Java / Spring Boot / Kafka / Kubernetes) 6 months (initially) Remote-working (UK-based) Market Rates (£550 to £575 per day) Outside IR35 The Opportunity: ISR Recruitment is currently supporting a leading consultancy client seeking an experienced Lead Java Engineer to design, build and deliver backend services for a national data exchange platform enabling secure data sharing between organisations. This is a hands-on technical leadership role, with no line-management responsibility where you will remain actively involved in coding and technical design while mentoring developers, supporting delivery and helping shape technical solutions. The platform is underpinned by zero-trust security principles and you will join a remote engineering team of 20+ people working on secure, scalable and production-critical services. You will take high-level or lightweight requirements, clarify what is required, translate them into technical specifications and...

Location: London (once a month) Department: Engineering Employment Type: Contract - Outside IR35 Contract Length: 6 months (with potential for extension) About YLD: Our goal is to help our clients keep moving forward. We work with them to build the skills and capabilities they need to stay ahead of the competition, and we know our success only happens when they succeed. We’re a team of curious, talented people, and we’re committed to making YLD a place where great people want to work, grow, and stay. We’re a remote-first consultancy specialising in software engineering, product design, and data. Our teams are based across London, Lisbon, and Porto, and we create digital solutions that continue to deliver value long after our work is done. About the role: As a Senior Software Engineer at YLD, you’ll be part of a client team building innovative products. We’re looking for someone curious, passionate, driven, and enthusiastic. You should be skilled in...