18 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...

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...

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)...

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...

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...

Senior Software Engineer | AI Enablement (Claude Code) £800–£900/day | Outside IR35 Preferred | London Hybrid (2 days/week) | ASAP I'm working with a leading Fintech looking for 4–5 experienced Software Engineers to help embed Claude Code across their engineering teams. This isn't a traditional AI Engineering role. You'll be working directly with developers, pairing, coaching and helping teams integrate Claude Code into their everyday engineering workflows. What you'll be doing: Working directly with backend and full-stack engineering teams to embed Claude Code into their daily development workflows. Pair programming and coaching engineers on effective AI-assisted development. Implementing and optimising CLAUDE.md files, custom slash commands, subagents, hooks and context management. Helping teams integrate AI into testing, CI/CD, code reviews and secure development practices. Identifying opportunities to improve engineering productivity and providing...

JOB TITLE: DevOps Engineer - DV Cleared Rate: £600-£650/day (Outside IR35) Location: Onsite in Basingstoke Clearance: DV Cleared (Mandatory) Job Summary We are seeking a technically skilled DevOps Engineer with DV clearance to contribute across the full software development lifecycle and DevOps toolchain. You will design, implement, and maintain scalable, secure, and automated CI/CD pipelines, infrastructure-as-code (IaC), and system monitoring frameworks to support the continuous delivery of secure and reliable software. This role demands a strong grasp of modern DevOps practices, cloud and container technologies, automation tooling, and software engineering principles. You will work closely with development, security, and operations teams to drive a culture of DevSecOps and continuous improvement. Key Responsibilities Design, build, and maintain scalable CI/CD pipelines using modern DevOps tooling. Implement Infrastructure-as-Code (IaC) to provision and...

JOB TITLE: DevOps Engineer - DV Cleared Rate: £600-£650/day (Outside IR35) Location: Onsite in Basingstoke Clearance: DV Cleared (Mandatory) Job Summary We are seeking a technically skilled DevOps Engineer with DV clearance to contribute across the full software development lifecycle and DevOps toolchain. You will design, implement, and maintain scalable, secure, and automated CI/CD pipelines, infrastructure-as-code (IaC), and system monitoring frameworks to support the continuous delivery of secure and reliable software. This role demands a strong grasp of modern DevOps practices, cloud and container technologies, automation tooling, and software engineering principles. You will work closely with development, security, and operations teams to drive a culture of DevSecOps and continuous improvement. Key Responsibilities Design, build, and maintain scalable CI/CD pipelines using modern DevOps tooling. Implement Infrastructure-as-Code (IaC) to provision and manage...