19 senior backend engineer jobs found

Senior Backend Engineer (Contract) | NodeJS / C# / Kotlin / Java / Go | London Hybrid | £550/£600 per day | Contract They're looking for Senior Backend Engineers who can do more than simply pick up tickets. They want people who are technically strong, proactive and comfortable taking ownership of projects, working collaboratively with the wider engineering team and delivering reliable, high-quality systems. This is an opportunity to join a busy engineering environment where you'll be working on meaningful product integrations, solving complex technical challenges and helping deliver some of the business's highest-priority projects. What You'll Be Doing • Building and delivering backend integrations across a range of product initiatives. • Designing and building reliable, scalable backend systems. • Working across authentication and identity-related functionality. • Taking ownership of projects, from understanding requirements through to delivery. •...

Senior Backend Engineer (Contract) | NodeJS / C# / Kotlin / Java / Go | London Hybrid | £550/£600 per day | Contract They're looking for Senior Backend Engineers who can do more than simply pick up tickets. They want people who are technically strong, proactive and comfortable taking ownership of projects, working collaboratively with the wider engineering team and delivering reliable, high-quality systems. This is an opportunity to join a busy engineering environment where you'll be working on meaningful product integrations, solving complex technical challenges and helping deliver some of the business's highest-priority projects. What You'll Be Doing • Building and delivering backend integrations across a range of product initiatives. • Designing and building reliable, scalable backend systems. • Working across authentication and identity-related functionality. • Taking ownership of projects, from understanding requirements through to delivery. •...

Senior Backend Engineer (Contract) | NodeJS / C# / Kotlin / Java / Go | London Hybrid | £550/£600 per day | Contract They're looking for Senior Backend Engineers who can do more than simply pick up tickets. They want people who are technically strong, proactive and comfortable taking ownership of projects, working collaboratively with the wider engineering team and delivering reliable, high-quality systems. This is an opportunity to join a busy engineering environment where you'll be working on meaningful product integrations, solving complex technical challenges and helping deliver some of the business's highest-priority projects. What You'll Be Doing • Building and delivering backend integrations across a range of product initiatives. • Designing and building reliable, scalable backend systems. • Working across authentication and identity-related functionality. • Taking ownership of projects, from understanding requirements through to delivery. •...

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...

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...

Contract Opportunity: Senior Front-End Engineer, Identity Integration 6 months | Outside IR35 | Hybrid, 2–3 days in London | £550–£700 per day (flexible) I’m working with a fast-growing fintech scale-up that has just been acquired by a global leader in financial and accounting software. As part of the acquisition, they’re bringing their platform together with one of the world’s most widely used small business accounting products. They need experienced contractors to help deliver that integration. The work centres on identity: connecting the two platforms so users can sign in and move between them securely and seamlessly. It’s a high-visibility project inside a newly combined business, with real technical ownership of the user-facing experience. What you’ll be doing: Building the user-facing sign-in, sign-up and account-linking journeys between the two platforms Implementing client-side authentication flows, including redirects, session handling and secure token...

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...

6-Month Contract | Outside IR35 | Hybrid London | ASAP Start We're working exclusively with an established investment management business seeking an experienced, hands-on Senior Full Stack Engineer to take a portfolio of internally developed applications and prototypes through UAT and into production. The business has been using AI-assisted development tools, including Claude, to rapidly develop working prototypes. These include Claude Artifacts and Azure-hosted web applications built using React, TypeScript and Next.js. The requirement is for an engineer who can assess and develop these applications into secure, scalable and maintainable production solutions, integrate them with existing systems and data sources and subsequently support the development of new business applications. This is a hands-on engineering role offering considerable autonomy, working closely with senior business stakeholders, domain experts and data engineers. Key responsibilities Assess...

Senior Full Stack Engineer (Python & Typescript) Location: Predominantly Remote Start Date: November 2026 Duration: Until March/April 2027 Rate: £500 – £525 per day IR35: Outside IR35 The Opportunity We are supporting a client operating within a highly regulated environment and looking to engage an experienced contract engineer to join a critical delivery programme This is an opportunity to join a fast-paced engineering team focused on delivering high-quality software solutions where hands-on development, AI-assisted engineering, and structured delivery practices are central to success. What We're Looking For Successful candidates will have experience working within heavily regulated or enterprise environments and be comfortable operating within formal governance frameworks, change controls, ticketing processes, and established development lifecycles. You'll bring: Proven experience delivering software solutions in regulated environments Strong...

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...

We're working exclusively with an established investment management business seeking an experienced, hands-on Full Stack .NET Engineer to take a number of internally developed applications and prototypes through to production. The business has been using AI-assisted development tools, including Claude, to rapidly develop working prototypes and now requires an engineer with the technical depth to turn these into secure, scalable and maintainable production applications. This is a backend-leaning full-stack role, with a strong emphasis on C#/.NET, Azure, application architecture and data integration. You'll also need sufficient frontend development experience to deliver complete, functional applications. Working directly with senior business stakeholders in a small technical environment, you'll have considerable autonomy and responsibility for technical delivery. Key responsibilities Take existing applications and prototypes through to production. Design, develop and...

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...

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 Full-Stack Java Engineer | Up to £550/day Outside IR35 | Bristol Hybrid About the role We're hiring a Senior Full-Stack Java Engineer on an initial 3-month contract for a PE-backed digital consultancy. The contract is likely to be extended. The client is building its own SaaS platform on Microsoft Azure. The platform connects data from enterprise systems and gives users dashboards, workflow, exception management and scenario analysis. You'll work hands-on with the Tech Lead across the whole product. The main focus is the Java and Spring Boot services, with work on the Node and React front ends and internal tooling too. Key responsibilities Build and harden Java 21+ and Spring Boot services, including user management, access control, audit and notifications Extend Node and TypeScript services that calculate metrics and serve dashboards Build data-dense React screens for dashboards, workflow and administration Develop the internal tooling used to configure and...

Senior Full-Stack Java Engineer | Up to £550/day Outside IR35 | Bristol Hybrid About the role We’re hiring a Senior Full-Stack Java Engineer on an initial 3-month contract for a PE-backed digital consultancy. The contract is likely to be extended. The client is building its own SaaS platform on Microsoft Azure. The platform connects data from enterprise systems and gives users dashboards, workflow, exception management and scenario analysis. You’ll work hands-on with the Tech Lead across the whole product. The main focus is the Java and Spring Boot services, with work on the Node and React front ends and internal tooling too. Key responsibilities Build and harden Java 21+ and Spring Boot services, including user management, access control, audit and notifications Extend Node and TypeScript services that calculate metrics and serve dashboards Build data-dense React screens for dashboards, workflow and administration Develop the internal tooling used to...

Contract status: Outside IR35 Start date: ASAP Contract length: Three months Location: Remote first Office days: Once or twice a year (London) Why this one You’ll work on the security-critical parts of a UK government Android app, including login. If you know mobile security properly and want to use it, this contract will test it. What’s in it for you You’ll work in native Kotlin and Jetpack Compose on a live government app. You’ll see how features from several teams come together in one app, and help shape how they fit. You’ll work from home most of the time. Who you’ll be doing it for You’ll join the mobile platform team on a UK government app. The team builds and maintains the common parts of the app, brings in features built by other teams, and manages releases. You’re engaged through hedgehog lab, a digital product consultancy that’s B Corp and Great Place to Work certified. For 20 years...

Contract status: Outside IR35 Start date: ASAP Contract length: Three months Location: Remote first Office days: Once or twice a month (London) 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 code is ready, you’ll put it up for review. You’ll review other people’s code too. Once a...

Python/React Full Stack Engineer 3-month contract (initially) Remote Working Outside-IR35 Market Rates (c£500 to £525 per day) The Opportunity: We are looking for a Full Stack Engineer with experience specifically with Python and React, to support the development of a public sector digital service, where you will be working within an Agile team, combining hands-on development with automation and operational delivery to build secure, reliable software. This opportunity suits engineers who enjoy building applications and taking responsibility for how they are tested, deployed and supported and is a hands-on role combining full stack software engineering, cloud deployment and DevOps practices. You will take ownership of changes throughout the delivery lifecycle, from backlog refinement and development through testing, deployment and operational handover, working across React and TypeScript interfaces, Python Back-End services and AWS infrastructure, taking features from...