11 api developer jobs found in London

Lead .NET/Full Stack Developer - Hybrid - £700/day Outside IR35 | C# | Azure | Event Driven Systems | Payments | API Driven We have a unique opportunity for a Lead .NET/Full Stack Developer to join a payments company. As the Lead .NET/Full Stack Developer , you’ll play a key role in shaping and scaling a high-throughput payments platform as the business enters its next phase of growth. This includes launching new products, enabling new partner integrations, and expanding a platform that already powers multiple live financial services products used globally. You’ll be building on top of a modern, cloud-native platform built with .NET and Azure , designed around API-first architecture and event-driven microservices . The platform supports complex payment flows, partner integrations, and high-volume transaction processing. This is a hands-on technical role where you’ll help drive engineering best practices, contribute to architectural decisions, and mentor...

Senior .NET / Full Stack Developer – Hybrid – £600/day Outside IR35 | C# | Azure | Event-Driven Systems | Payments | API-Driven We have a unique opportunity for a Senior .NET / Full Stack Developer to join a payments company. As a Senior .NET / Full Stack Developer , you’ll play a key role in building and scaling a high-throughput payments platform as the business enters its next phase of growth. This includes launching new products, enabling new partner integrations, and expanding a platform that already powers multiple live financial services products used globally. You’ll be building on top of a modern, cloud-native platform built with .NET and Azure , designed around API-first architecture and event-driven microservices . The platform supports complex payment flows, partner integrations, and high-volume transaction processing. This is a hands-on senior engineering role where you’ll contribute to architectural discussions, drive engineering best...

Java Developer - SC Cleared Location: London (1–2 days onsite per month) Contract: Outside IR35 Rate: £600–£675 per day Duration: 12 Month Contract Start: Immediate / Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Java Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. Requirements Strong experience with Java & Springboot Solid Java back-end development experience Experience working in public sector Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

Full Stack Developer (React / TypeScript / Java) Location: London (1–2 days onsite per month) Contract: Outside IR35 Rate: £650–£700 per day Duration: 12 Month Contract Start: Immediate / Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Full Stack Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. The role requires a 50/50 split across front-end and back-end development . Requirements Strong experience with React and TypeScript Solid Java back-end development experience Experience working in a full stack capacity (approx. 50/50 front-end/back-end) Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

Java Developer - SC Cleared Location: London (1-2 days onsite per month) Contract: Outside IR35 Rate: £600-£675 per day Duration: 12 Month Contract Start: Immediate/Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Java Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. Requirements Strong experience with Java & Springboot Solid Java Back End development experience Experience working in public sector Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

Full Stack Developer (React/TypeScript/Java) Location: London (1-2 days onsite per month) Contract: Outside IR35 Rate: £650-£700 per day Duration: 12 Month Contract Start: Immediate/Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Full Stack Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. The role requires a 50/50 split across Front End and Back End development . Requirements Strong experience with React and TypeScript Solid Java Back End development experience Experience working in a full stack capacity (approx. 50/50 Front End/Back End) Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

Mulesoft Developer - Outside IR35 - 6 months We're looking for an experienced MuleSoft Developer to support an integration programme connecting enterprise systems including CRM and ERP platforms. You'll be responsible for designing and building integrations using the MuleSoft Anypoint Platform, working closely with internal teams to deliver API-led integrations and improve system interoperability. Key responsibilities Develop and maintain integrations using MuleSoft Build and document APIs using the Anypoint platform Support integration architecture and API specifications Debug, troubleshoot and resolve integration issues Write unit tests and maintain clean, well-structured code Support integration testing and deployment Experience required Strong hands-on experience with MuleSoft/Anypoint Platform Experience building API-led integrations Experience integrating CRM and ERP platforms Strong API, REST and...

Position: App Developer Location: Vauxhall/Stratford Day Rate: £600 p.d Outside IR35 Must hold active DV clearance A central government department is looking for an experienced App Developer to join a high-security programme. This role requires working on-site 5 days per week in Vauxhall, moving later to Stratford later on in the project. Due to the nature of the work, candidates hold UKSV DV clearance. Key Skills & Experience Strong expertise in Python, Docker, Kubernetes, and Data Governance Experience working in air-gapped environments, including managing dependencies and build pipelines without Internet access Proven background building APIs for data enrichment services Orchestration & data pipeline experience with Prefect or Airflow, and K8s or Swarm Configuration and automation of business workflow tooling (eg, Jira) Hands-on experience with a range of databases and storage technologies: Elastic, Mongo, Cassandra, Redis, S3 Desirable Skills...

IT Applications Manager - Central London £650 - £700 p/d (outside IR35) - 3 month initial term Well-established and highly profitable construction engineering business is seeking an experienced IT Applications Manager to join them on a permanent basis. This is a critical leadership role within an organisation undergoing significant digital transformation, with ambitious growth and acquisition plans driving demand for scalable, standardised and efficient business applications. Reporting into the Head of IT, you will lead the delivery, governance and optimisation of business applications across the enterprise. This role blends strategic oversight, hands-on expertise with modern low-code/no-code platforms and direct leadership of a multidisciplinary applications team. The IT Applications Manager will oversee a suite of core enterprise systems, including but not limited to: Workday, UKG (Kronos), COINS, SharePoint, Snowflake, Autodesk Construction Cloud, Pro-Sapien,...

IT Applications Manager - Central London (hybrid) £650 - £700 p/d (outside IR35) 3 month initial term, likely to extend Well-established and highly profitable construction engineering business is seeking an experienced IT Applications Manager to join them on a permanent basis. This is a critical leadership role within an organisation undergoing significant digital transformation, with ambitious growth and acquisition plans driving demand for scalable, standardised and efficient business applications. Reporting into the Head of IT, you will lead the delivery, governance and optimisation of business applications across the enterprise. This role blends strategic oversight, hands-on expertise with modern low-code/no-code platforms and direct leadership of a multidisciplinary applications team. The IT Applications Manager will oversee a suite of core enterprise systems, including but not limited to: Workday, UKG (Kronos), COINS, SharePoint, Snowflake, Autodesk...

IT Applications Manager - Central London £650 - £700 p/d (outside IR35) - 3 month initial term Well-established and highly profitable construction engineering business is seeking an experienced IT Applications Manager to join them on a permanent basis. This is a critical leadership role within an organisation undergoing significant digital transformation, with ambitious growth and acquisition plans driving demand for scalable, standardised and efficient business applications. Reporting into the Head of IT, you will lead the delivery, governance and optimisation of business applications across the enterprise. This role blends strategic oversight, hands-on expertise with modern low-code/no-code platforms and direct leadership of a multidisciplinary applications team. The IT Applications Manager will oversee a suite of core enterprise systems, including but not limited to: Workday, UKG (Kronos), COINS, SharePoint, Snowflake, Autodesk Construction Cloud, Pro-Sapien, Primavera P6...