25 full stack developer jobs found in London

We're recruiting an experienced Full Stack Developer to help build a greenfield trading platform for a financial services business. This is a full-stack role with a strong Front End/UI emphasis. You'll lead on responsive, Real Time trading interfaces using Next.js and React, while also contributing to Back End services, APIs and integrations. This role is outside IR35 and requires 3 days per week onsite in London. Key requirements: Strong trading application UI experience using Next.js, React, TypeScript, Web Components and AG Grid. Real Time communication using WebSocket or SignalR. Backend development with C#, .NET 8, Python, RESTful APIs and Web API. Distributed systems and microservices, with RabbitMQ or Kafka messaging. Experience with Redis caching and Protobuf. SQL Server, AWS RDS and MongoDB or similar NoSQL databases. Azure/AWS, including application authentication. Azure DevOps, Git/GitHub, CI/CD pipelines and...

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 life cycles. You'll bring: Proven experience delivering software solutions in regulated environments Strong...

6 month contract, fully remote Full Stack Developer - .NET and React Up to £350 per day outside IR35 A retail company are hiring for a Senior Full Stack Engineer to join their order fulfilment team to help design, build and evolve the digital platform. This is a hands-on role where you'll work closely with product and engineering teams to solve real business problems and deliver impactful digital experiences. It is a modern engineering function that uses agentic AI tools throughout its development process. Responsibilities Design build and maintain scalable secure and high-performing E-commerce applications using React C# .NET and Azure Deliver end-to-end features across the stack from Front End experience through to Back End services Work in short iterative cycles alongside product and E-commerce teams Contribute to the design of cloud-native architectures on Microsoft Azure Build and maintain robust APIs and services using .NET Develop responsive...

Full Stack Developer Engineer - Cyber DevOps Rate: £450 (Outside IR35) Location: Remote Contract: 3-6 months Python | FastAPI | JavaScript | React | AWS We're looking for an experienced Full Stack Developer to join a growing Cyber DevOps team, developing innovative applications, automation and engineering tools used across Cyber Security and Network environments. This is an opportunity to work on a varied range of development projects, taking ownership across the full software development lifecycle, from designing and building backend services and APIs through to frontend development, cloud deployment and production support. You'll be working with modern technologies to build secure, scalable and reliable solutions that support critical engineering environments. What will you be doing? Designing, developing and maintaining full-stack applications and internal engineering tools. Building backend services, REST APIs and automation solutions using Python and FastAPI....

Full Stack Developer (Python/React/AWS) Contract: Outside IR35 Location: Hybrid Working (UK) Day Rate: Competitive Duration: Initial contract with extension potential We're seeking an experienced Full Stack Developer to join a high-performing technology team, delivering applications, automation solutions, and engineering tools that support complex operational environments. This is a hands-on role where you'll work across the full software development lifecycle, designing, building, and supporting scalable applications using modern technologies across both cloud and on-premise environments. Key Responsibilities Design, develop, and maintain full-stack applications and internal tooling. Build Back End services, APIs, and automation solutions using Python and FastAPI. Develop modern web applications using JavaScript and React. Design and optimise PostgreSQL databases. Deploy and support applications within AWS environments. Build and maintain CI/CD...

Full Stack Developer - 3-month contract - £500 per day (Outside IR35) - Berkshire/Hybrid (2 days a week on site) Python/React JS/PostgreSQL/SQL/FastAPI/AWS/Cyber Security Key skills/responsibilities: Design, develop and maintain full-stack applications and internal engineering tools. Build Back End services, APIs and automation primarily using Python. Develop modern web interfaces using JavaScript/TypeScript and associated frameworks. Design and work with relational databases, particularly PostgreSQL. Develop, deploy and support applications within AWS environments. Build and maintain CI/CD pipelines and automated deployment processes. Troubleshoot application, infrastructure and integration issues across the stack. Apply secure development practices throughout the software lifecycle Strong Python FastAPI development experience and extensive React JS experience Strong knowledge of SQL and PostgreSQL. Experience developing both Back End and Front End...

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 fa click apply for full job details

Full Stack Developer Engineer - Cyber DevOps Rate: £450 (Outside IR35) Location: Remote Contract: 3-6 months Python FastAPI JavaScript React AWS We're looking for an experienced Full Stack Developer to join a growing Cyber DevOps team, developing innovative applications, automation and engineering tools used across Cyber Security and Network environments click apply for full job details

Full-Stack Developers – React, React Native & .NET | Maritime Defence Security clearance — Current UK SC clearance preferred. Applicants eligible to obtain SC may be considered, subject to confirmation. Active SC is required for site attendance. About the opportunity Puma Berry is seeking two Full-Stack Developers, one mid-level and one senior , for an upcoming maritime defence software programme. You will help develop applications that enable users to record vessel inspections, capture survey data and synchronise information across connected and offline environments. Working within an established Agile team, you will contribute across web, mobile and backend development alongside business analysts, designers, developers and testers. These opportunities are subject to contract award. Contract details Rate — £425–£525 per day, depending on experience and role level. IR35 status — Expected to be outside IR35, subject to...

Full-Stack Developers – React, React Native & .NET | Maritime Defence Security clearance — Current UK SC clearance preferred. Applicants eligible to obtain SC may be considered, subject to confirmation. Active SC is required for site attendance. About the opportunity Puma Berry is seeking two Full-Stack Developers, one mid-level and one senior , for an upcoming maritime defence software programme. You will help develop applications that enable users to record vessel inspections, capture survey data and synchronise information across connected and offline environments. Working within an established Agile team, you will contribute across web, mobile and backend development alongside business analysts, designers, developers and testers. These opportunities are subject to contract award. Contract details Rate — £425–£525 per day, depending on experience and role level. IR35 status — Expected to be outside IR35, subject to...

KeyStream are looking to find an experienced Senior Full Stack Application Developer to support a major NHS digital transformation programme. This is an exciting contract opportunity for an accomplished software developer with strong Microsoft technologies experience to contribute to the delivery of innovative digital solutions that support clinical and operational services across a large healthcare environment. Working within a busy Digital Applications function, you will be responsible for designing, developing and enhancing applications, integrations and cloud-based solutions that improve user experience, operational efficiency and service delivery. You will also have the opportunity to work with emerging technologies, including AI-enabled solutions, as part of ongoing digital innovation initiatives. Responsibilities Design, develop and support full stack applications and digital solutions. Build and maintain APIs, integrations and automated workflows. Work closely...

Full Stack Engineer | Cross Asset Trading | React, C#, .NET, SQL Server | London | Hybrid 1-2 days onsite | Up to £550 p/day | Outside IR35 We’re working with a cross-asset trading business that’s firmly tech-first, where engineering sits at the heart of how the firm operates. They’re looking for a Full Stack Developer to join on a contract basis and help build the applications their traders and teams rely on every day. On the technical side, this is a front end-led role, with roughly 60% of your time in React, 30% across .NET, C# and API development, and the remaining 10% in SQL Server. Experience with the modern React ecosystem will set you apart, particularly the TanStack suite, which has become the industry standard for data access and routing. Just as important, you’ll bring a background in regulated environments. Finance can be a tricky space to step into cold, so a solid grasp of the vocabulary and an understanding of models and funds work will help you hit the...

Full Stack Engineer | Cross Asset Trading | React, C#, .NET, SQL Server | London | Hybrid 1-2 days onsite | Up to £550 p/day | Outside IR35 We’re working with a cross-asset trading business that’s firmly tech-first, where engineering sits at the heart of how the firm operates. They’re looking for a Full Stack Developer to join on a contract basis and help build the applications their traders and teams rely on every day. On the technical side, this is a front end-led role, with roughly 60% of your time in React, 30% across .NET, C# and API development, and the remaining 10% in SQL Server. Experience with the modern React ecosystem will set you apart, particularly the TanStack suite, which has become the industry standard for data access and routing. Just as important, you’ll bring a background in regulated environments. Finance can be a tricky space to step into cold, so a solid grasp of the vocabulary and an understanding of models and funds work will help you hit the...

Full Stack Engineer | Cross Asset Trading | React, C#, .NET, SQL Server | London | Hybrid 1-2 days onsite | Up to £550 p/day | Outside IR35 We’re working with a cross-asset trading business that’s firmly tech-first, where engineering sits at the heart of how the firm operates. They’re looking for a Full Stack Developer to join on a contract basis and help build the applications their traders and teams rely on every day. On the technical side, this is a front end-led role, with roughly 60% of your time in React, 30% across .NET, C# and API development, and the remaining 10% in SQL Server. Experience with the modern React ecosystem will set you apart, particularly the TanStack suite, which has become the industry standard for data access and routing. Just as important, you’ll bring a background in regulated environments. Finance can be a tricky space to step into cold, so a solid grasp of the vocabulary and an understanding of models and funds work will help you hit the...

Full Stack Software Developer Active SC TypeScript/React/Node.js Overview Outside IR35 £500-£540 a day Remote + adhoc onsite in South coast location Start ASAP 6 Month Contract Active SC - essential SR2 is recruiting an experienced Full Stack Developer to join an exciting greenfield project within a highly regulated area. This is a fantastic opportunity to build a brand-new TypeScript codebase from the ground up, working across both Front End and Back End development. You'll have plenty of autonomy, working closely with the Technical Lead to shape technical decisions, engineering standards and the overall solution. Due to the secure nature of this work applicants must already have active SC clearance. Unfortunately, due to the quick turn around required, we cannot put you through this if you do not already have it. Key Skills & Experience: Front End: TypeScript, React, modern CSS, accessibility Back End: TypeScript, Node.js, REST APIs,...

Full Stack Software Developer Active SC TypeScript/React/Node.js Overview Outside IR35 £500-£540 a day Remote + adhoc onsite in South coast location Start ASAP 6 Month Contract Active SC - essential SR2 is recruiting an experienced Full Stack Developer to join an exciting greenfield project within a highly regulated area. This is a fantastic opportunity to build a brand-new TypeScript codebase from the ground up, working across both Front End and Back End development. You'll have plenty of autonomy, working closely with the Technical Lead to shape technical decisions, engineering standards and the overall solution. Due to the secure nature of this work applicants must already have active SC clearance. Unfortunately, due to the quick turn around required, we cannot put you through this if you do not already have it. Key Skills & Experience: Front End: TypeScript, React, modern CSS, accessibility Back End: TypeScript, Node.js, REST APIs,...

FULLY REMOTE OUTSIDE IR35 We are looking for a Full Stack Developer with strong Node.js skills to develop and support frontend and backend systems. A central part of the role is connecting our AI platform with internal and third-party services through APIs and Model Context Protocol (MCP) integrations. You will build features across the application stack and help ensure they operate reliably in production. Key responsibilities Develop backend services in Node.js and JavaScript/TypeScript. Build and maintain frontend functionality using an appropriate modern web framework. Design, implement, document and integrate APIs connecting our platform, customer applications and external services. Develop MCP clients and servers that expose approved tools, resources and capabilities to AI applications. Define and validate JSON schemas, API contracts and integration payloads. Implement authentication, authorisation, secrets management and appropriate access controls. Build database...

About Us: Solirius Reply, part of the Reply Group, is a technology consultancy and digital transformation partner that helps organisations solve complex challenges through strategy, design, engineering, and delivery. We work closely with our clients to deliver secure, accessible, user-focused services that evolve with their needs. By combining deep technical expertise with people-centred design, we create solutions that deliver meaningful, lasting impact. Our consultants partner directly with client teams, embedding into organisations to understand their goals, challenges, and users. This collaborative approach enables us to deliver tailored solutions that drive measurable outcomes across public and private sectors. Past and present clients include the Ministry of Justice, Department for Education, Ministry of Housing, Communities and Local Government, UEFA, International Olympic Committee, and Mercedes-Benz. Our services span the full digital delivery life cycle,...

SC Cleared Typescript Engineer / Outside IR35/ Occasional Travel / 12 month Contract  We’re looking for an experienced Full Stack Javascript Developer to join a greenfield digital programme within a secure environment. You’ll be working across the full stack, helping build a new TypeScript-based platform from the ground up and taking genuine ownership of features from development through to production. Essential Experience  Active SC  Strong TypeScript experience across front and back end React Node.js and REST APIs PostgreSQL, including schema design and query optimisation Unit, integration and end-to-end testing Docker and containerised applications CI/CD, ideally GitHub Actions OIDC / Keycloak authentication Agile delivery experience Bonus: Experience with Kubernetes/OpenShift, Terraform/Helm, Grafana, Prometheus or Loki would be beneficial.  If you are interested in this role and have relevant experience, please apply or email your latest CV to (url removed)...

SC Cleared Typescript Engineer/Outside IR35/Occasional Travel/12 month Contract We're looking for an experienced Full Stack Javascript Developer to join a greenfield digital programme within a secure environment. You'll be working across the full stack, helping build a new TypeScript-based platform from the ground up and taking genuine ownership of features from development through to production. Essential Experience Active SC Strong TypeScript experience across front and back end React Node.js and REST APIs PostgreSQL, including schema design and query optimisation Unit, integration and end-to-end testing Docker and containerised applications CI/CD, ideally GitHub Actions OIDC/Keycloak authentication Agile delivery experience Bonus: Experience with Kubernetes/OpenShift, Terraform/Helm, Grafana, Prometheus or Loki would be beneficial. If you are interested in this role and have relevant experience, please apply or email your latest CV to (see below)...