1 to 25 of 27 Contract API Development Jobs in the UK

Job Title: API Developer Location: Remote Contract Length: 3 months Start Date: ASAP iO Associates are working with an exciting UK Based Defence company that blends strategic modelling, specialist analytics, and operational insight to simplify complex challenges and empower decisive thinking. They are looking for an API Developer to join the team for 3 months to support one … that transform complex data into actionable insights, all within a culture that values autonomy and innovation. Key Responsibilities: Requirements Analysis : Employ structured methods to capture and assess technical requirements. API Development : Design and implement secure, scalable APIs using Python or Java. System Integration : Integrate third-party services and data sources. Task Structuring : Organise tasks into functional work packages … implementation, acceptance). Stakeholder Collaboration : Work closely with stakeholders and technical assurers to ensure quality delivery. Prioritisation & Validation : Apply MoSCoW prioritisation and scenario analysis for requirement validation. Essential Skills: API Development : Proficiency in Python or Java for building RESTful and GraphQL APIs. Agile Methodologies : Experience with structured delivery frameworks and Agile practices. Development Tools : Familiarity with Swagger More ❯

extension or permanent opportunities Location : Farnborough (2 days onsite) + 3 days remote Industry : Automotive Technology Solutions Client : Major automotive industry leader via global consultancy partnership Technical Requirements Backend Development C# .NET Framework/Core - Extensive experience developing robust, scalable backend services RESTful API Development - Design and implementation of web APIs Microservices Architecture - Understanding of distributed systems … and service-oriented architecture Frontend Development Blazor - Proficiency in Blazor Server and/or Blazor WebAssembly React.js - Strong experience including hooks, state management, and modern development practices JavaScript/TypeScript - Advanced knowledge of modern JavaScript and TypeScript HTML5/CSS3 - Solid understanding of web standards, responsive design, and cross-browser compatibility Database Technologies Oracle (Preferred) - Database development … SQL, and performance optimization SQL Server (Alternative) - T-SQL and database design experience acceptable Entity Framework - ORM experience for data access layer implementation Essential Requirements 5+ years full stack development experience Software Development Lifecycle - Strong understanding of SDLC and Agile methodologies Version Control - Git experience CI/CD & DevOps - Knowledge of continuous integration pipelines Security Best Practices - Web More ❯

extension or permanent opportunities Location : Farnborough (2 days onsite) + 3 days remote Industry : Automotive Technology Solutions Client : Major automotive industry leader via global consultancy partnership Technical Requirements Backend Development C# .NET Framework/Core - Extensive experience developing robust, scalable backend services RESTful API Development - Design and implementation of web APIs Microservices Architecture - Understanding of distributed systems … and service-oriented architecture Frontend Development Blazor - Proficiency in Blazor Server and/or Blazor WebAssembly React.js - Strong experience including hooks, state management, and modern development practices JavaScript/TypeScript - Advanced knowledge of modern JavaScript and TypeScript HTML5/CSS3 - Solid understanding of web standards, responsive design, and cross-browser compatibility Database Technologies Oracle (Preferred) - Database development … SQL, and performance optimization SQL Server (Alternative) - T-SQL and database design experience acceptable Entity Framework - ORM experience for data access layer implementation Essential Requirements 5+ years full stack development experience Software Development Lifecycle - Strong understanding of SDLC and Agile methodologies Version Control - Git experience CI/CD & DevOps - Knowledge of continuous integration pipelines Security Best Practices - Web More ❯

extension or permanent opportunities Location : Farnborough (2 days onsite) + 3 days remote Industry : Automotive Technology Solutions Client : Major automotive industry leader via global consultancy partnership Technical Requirements Backend Development C# .NET Framework/Core - Extensive experience developing robust, scalable backend services RESTful API Development - Design and implementation of web APIs Microservices Architecture - Understanding of distributed systems … and service-oriented architecture Frontend Development Blazor - Proficiency in Blazor Server and/or Blazor WebAssembly React.js - Strong experience including hooks, state management, and modern development practices JavaScript/TypeScript - Advanced knowledge of modern JavaScript and TypeScript HTML5/CSS3 - Solid understanding of web standards, responsive design, and cross-browser compatibility Database Technologies Oracle (Preferred) - Database development … SQL, and performance optimization SQL Server (Alternative) - T-SQL and database design experience acceptable Entity Framework - ORM experience for data access layer implementation Essential Requirements 5+ years full stack development experience Software Development Lifecycle - Strong understanding of SDLC and Agile methodologies Version Control - Git experience CI/CD & DevOps - Knowledge of continuous integration pipelines Security Best Practices - Web More ❯

major integration project within a high-integrity engineering environment. Our client, a respected UK leader in mission-critical software and systems, is seeking a capable contractor to assist with API development and systems integration involving Oracle and internal platforms. This role requires a proactive engineer who can take ownership of specific, well-defined technical tasks. Key Skills Required … on experience with Atlassian tools (Jira, Confluence) Strong PowerShell scripting skills Solid knowledge of SQL Server or similar relational databases Experience working with or integrating Oracle systems Familiarity with API development and integration Ability to work independently and efficiently on scoped tasks UK nationality is essential due to project requirements Experience in regulated sectors is beneficial (e.G. Defence More ❯

Axway API Developer + 6 month initial contract + Full remote + 650 to 690 per day + SC Cleared role Key Skills: + Axway API Development/Administration + SC Clearance Responsibilities Designing, developing and deploying of Axway policies and containers using Axway Policy Studio v7.7 Working with DevOps toolset for develop and maintain Automated Testing … and Code Deployment Provide Assistance to Axway support team to resolve technical issues Administrating the Axway Environment, using Axway Policy Studio, Axway API Manager, Cassandra and API Gateway for Deployment of Axway Patches, monitor capacity, providing service improvements Liaise with customers to define project requirements, document and design solutions Knowledge of: SFTP HTTPS SSL/TLS oAuth JSON More ❯

Axway API Developer + 6 month initial contract + Full remote + £650 to £690 per day + SC Cleared role Key Skills: + Axway API Development/Administration + SC Clearance Responsibilities Designing, developing and deploying of Axway policies and containers using Axway Policy Studio v7.7 Working with DevOps toolset for develop and maintain Automated Testing … and Code Deployment Provide Assistance to Axway support team to resolve technical issues Administrating the Axway Environment, using Axway Policy Studio, Axway API Manager, Cassandra and API Gateway for Deployment of Axway Patches, monitor capacity, providing service improvements Liaise with customers to define project requirements, document and design solutions Knowledge of: SFTP HTTPS SSL/TLS oAuth JSON More ❯

and production-grade digital solutions for the financial services sector. This is a hands-on engineering role ideal for someone with strong experience in Java , Spring Boot , microservices , and API development , who thrives in collaborative, high-accountability environments. The successful candidate will contribute to backend service design, secure API delivery, and the development of reusable engineering … Key Responsibilities Design, develop, and maintain backend services using Java and Spring Boot Build and integrate secure APIs aligned with industry standards (e.g., OAuth2, OpenID Connect) Contribute to the development of microservices architectures and distributed systems Collaborate with frontend, DevOps, and QA teams to deliver cohesive, end-to-end solutions Participate in technical design sessions, code reviews, and architecture … Ensure adherence to Agile delivery practices, CI/CD pipelines, and DevSecOps principles Required Skills and Experience Strong hands-on experience with Java , Spring Boot , and enterprise-grade backend development Proven experience designing and implementing secure APIs and service integrations Solid understanding of microservices architecture , service orchestration, and distributed systems Experience working in regulated environments such as banking, fintech More ❯

with cross-functional teams to translate requirements into technical solutions Optimise application performance and ensure scalability, maintainability, and security best practices are met Stay up to date with web development trends, frameworks, and emerging technologies relevant to data applications EXPECTATIONS IN THE ROLE The following skills and attributes are essential for success in this role: Full-Stack Web Development … from front-end to back-end, with a focus on integrating data sources Data Visualisation Proficiency: Skilled in using D3.JS (or similar libraries) for rich, interactive graphics and charts API Integration Experience: Proven track record of consuming and building APIs for data exchange UI/UX Awareness: Understanding of user-centred design principles and the ability to collaborate on … a consulting or enterprise environment Proficiency in HTML, CSS, JavaScript, and frameworks such as React, Angular, or Vue.js Experience with D3.JS or similar advanced visualisation libraries Strong understanding of API development and integration (REST, GraphQL) Familiarity with database technologies and query languages (SQL, NoSQL) Experience working with data sources such as Microsoft Fabric’s Data Lake, Power.B.I., Qlik More ❯

Your New Company and Role A forward-thinking public sector organisation is looking for an experienced Java Developer to join a collaborative, agile team working on the development and enhancement of key digital services. You'll be contributing to the greenfield development of a new digital service and enhancing existing platforms to improve user experience, accessibility, and operational … to work in a multi-functional team that values continuous improvement, collaboration, and technical excellence. What You'll Need to Succeed You'll bring strong commercial experience in Java development and a passion for building robust, user-centred digital services. Key skills and experience include:Essential Skills Java 17+ and Spring Boot microservices REST API development SQL … and data modelling (ideally PostgreSQL) AWS and OpenShift CI/CD and modern DevOps practices Cloud monitoring and observability tools Infrastructure as CodeDesirable Skills Front-end development with React, HTML/CSS, and accessibility awareness AWS services such as Lambda, S3, Aurora, API Gateway, CDK, CloudFormation Testing frameworks like Cypress Jenkins, Docker OAuth2, Spring Web Flow, Spring MVC More ❯

Your New Company and Role A forward-thinking public sector organisation is looking for an experienced Java Developer to join a collaborative, agile team working on the development and enhancement of key digital services. You'll be contributing to the greenfield development of a new digital service and enhancing existing platforms to improve user experience, accessibility, and operational … to work in a multi-functional team that values continuous improvement, collaboration, and technical excellence. What You'll Need to Succeed You'll bring strong commercial experience in Java development and a passion for building robust, user-centred digital services. Key skills and experience include: Essential Skills Java 17+ and Spring Boot microservices REST API development SQL … and data modelling (ideally PostgreSQL) AWS and OpenShift CI/CD and modern DevOps practices Cloud monitoring and observability tools Infrastructure as Code Desirable Skills Front-end development with React, HTML/CSS, and accessibility awareness AWS services such as Lambda, S3, Aurora, API Gateway, CDK, CloudFormation Testing frameworks like Cypress Jenkins, Docker OAuth2, Spring Web Flow, Spring More ❯

Developer 6 months contract Day Rate: £365/day (Inside IR35) Location: Farnborough, UK (Hybrid 2 days on-site/week) About the Role: Youll be contributing to the development and enhancement of business-critical financial applications, building RESTful APIs and front-end components within a microservices-based architecture. The role offers the chance to work closely with analysts … operation of applications. Follow industry best practices and internal compliance standards. Required Skills & Experience: 8+ years of hands-on experience with .NET, C#, and Angular Strong experience with RESTful API development in microservice environments Solid understanding of .NET Core and event-driven architecture Experience working in Agile environments with cross-functional teams Familiarity with tools like JIRA, Confluence More ❯

dashboards, and generate ad hoc Power BI reports from Snowflake data tables. You will also integrate defect management and remediation capabilities for user owners/operators, ensuring compliance with development standards. Key Responsibilities: Workflow Tool Development: Architect and develop a robust tool to capture email traffic and translate it into actionable work queues and dashboards. Defect Management and … track, and remediate issues. Data Integration: Design and implement integration with Snowflake data tables for generating ad hoc Power BI reports. Compliance and Standards: Ensure adherence to companies established development standards and compliance requirements. Dashboard Creation: Develop insightful dashboards for real-time visibility into workflow processes and performance indicators. Collaboration: Work closely with the Transformation Portfolio Manager and stakeholders … project objectives with business needs. Technical Leadership: Provide guidance throughout the project lifecycle, from initial design through deployment and support. Documentation: Maintain comprehensive documentation of architecture, design decisions, and development processes. Quality Assurance: Implement rigorous testing and quality assurance practices to ensure tool reliability and performance. Skills and Experience: Highly skilled in interpreting business requirements and translating them into More ❯

student experience. How youll spend your day Build and Maintain Integrations : Design, implement, and maintain integrations that enable customers to connect their internal systems with the CAS Shield platform. API Development : Develop and optimize APIs and tools to ensure seamless interaction between our platform and customer systems. Collaboration : Work closely with product managers, engineers, and customer support teams … with the willingness to learn). Hands-on experience with SQL-based and NoSQL (Document-based) databases. Deep understanding of AWS services and cloud environments. Familiarity with AWS Cloud Development Kit (CDK)and services like Lambda, SQS, S3, Cognito, EventBridge, and more. Experience with DevOps practices, including CI/CD pipelines, Docker, and GitHub Actions. Strong knowledge of security … best practices for APIs and data privacy. Proficiency in unit, integration, and API testing using Jest. Ability to optimize software for performance and cost-efficiency in cloud environments. Excellent problem-solving abilities and troubleshooting skills. Strong communication and collaboration skills, with the ability to convey complex concepts to diverse audiences. Detail-oriented with a commitment to delivering high-quality More ❯

of the Cloud platform teams, playing a key role in developing software which makes a real impact to peoples’ lives The team you'll join are currently completing the development of the suite of micro-services (e.g. Tenancy Admin, Notifications) written in C# and built on the AWS architecture that will comprise our first Cloud Platform, due live later … Extensive knowledge and proven experience as a software developer, with exposure to elements of our back-end technology stack (C#, .Net) Good experience working with Amazon Web Services, Microservices, API development Knowledge and application of software engineering practices (e.g. Unit testing, TDD, CI/CD, SOLID, BDD etc.) and experience working as part of an agile delivery team. … Continuous delivery, with pipelines implemented in Kubernetes, Docker Front-End JavaScript Frameworks, especially Angular is advantageous Experience implementing and maintaining Datadog Experience using GitHub and GitHub Actions Behaviour Driven Development (BDD), with Gherkin & SpecFlow Atlassian Jira, Confluence & JFrog Artifactory Ideally some software security best practices and implementation (e.g. OWASP, PKI, X509 Certificates, TLS) Software development for regulated environments More ❯

Node.js, and TypeScript Lead the migration of existing systems from Node.js to Java to align with our strategic infrastructure goals Work with Docker and Kubernetes for containerization and streamlined development Build and manage CI/CD pipelines with GitHub Actions Monitor and maintain system performance, uptime, and deployments Write thorough unit and integration tests to ensure robust, reliable code … Collaborate with cross-functional teams to deliver innovative new features What We're Looking For: Extensive professional experience in backend development with Java and Node.js/TypeScript Solid knowledge of containerization tools (Docker, Kubernetes) Experience managing CI/CD pipelines with GitHub and GitHub Actions Strong understanding of SQL database management Computer Science or related degree Bonus Points For … Experience with Snowflake cloud data warehousing API development using GraphQL Soft Skills: Team player who thrives in a collaborative environment Strong problem-solving skills and ability to meet tight deadlines Effective communicator and adaptable to new tech Why Join Us? Work in London's financial hub with a leading institution committed to innovation and quality. Enjoy a hybrid More ❯

technical issues. Experience with system integrations (APIs, web services, batch processes). Knowledge of SaaS/cloud technologies and basic network configuration. Understanding of enterprise security principles and secure development practices. Experience in API development and management (RESTful, SOAP). Proven track record in supporting enterprise platforms and enhancing system capabilities. Excellent communication skills, both technical and … non-technical. Familiarity with ITIL Service Delivery framework. Technical Proficiency Cloud platforms and SaaS/PaaS solutions Application and PAS configuration API management and integration Mimecast, performance testing, patch and group policy management Understanding of security, data and reporting (desirable), Microsoft & Google products, SaaS licensing and commercials Culture and Conduct Be a role model for the organisation's purpose More ❯

teams to support CI/CD pipelines Manage cookies and session handling effectively Write and maintain unit tests using JUnit Work with POJOs and mock data for testing and development Integrate front-end components using Thymeleaf and JSON What you'll need to succeed Essential Skills: Java (Core and Advanced) Spring Boot & Spring Framework jQuery Thymeleaf RESTful API development and testing (Postman, Swagger) CI/CD pipelines and DevOps collaboration Cookies/session management Unit testing with JUnit Handling POJOs and mock data Desirable: Exposure to modern frontend frameworks (e.g., React, Angular, Vue) What you'll get in return Location: Liverpool (2-3 days on-site per week)?? Contract Length: 6 months? Rate: Competitive, Inside IR35 More ❯

in secure government environments. Youll bring: Python and/or JavaScript/TypeScript experience, strong AWS skills, Kubernetes, CI/CD, and experience with data platforms, high-volume processing, API development, and Terraform. Exposure to Helm, Argo, or Tekton is a plus. This is an opportunity to work in a fast-paced, mission-critical setting with hybrid flexibility More ❯

a critical platform for a Central Government body. We're seeking a seasoned Python, Postgres & React Developer to join a lean, agile team. You'll be hands-on developing API integrations, automation, and building a clean, maintainable codebase within a pragmatic, minimal tech stack. The environment is start-up-like - flexibility is essential. You'll wear multiple hats, operate … solutions without needing handholding. Key Skills: Strong Python & Postgres experience are a must JavaScript & React proficiency would be valuable - but not essential as they have a dedicated React Developer API development & integration expertise Automation workflows We need a contractor who thrives in ambiguity, values simplicity in solutions, and can crack on with little oversight. If you're a More ❯

a critical platform for a Central Government body. We're seeking a seasoned Python, Postgres & React Developer to join a lean, agile team. You'll be hands-on developing API integrations, automation, and building a clean, maintainable codebase within a pragmatic, minimal tech stack. The environment is start-up-like - flexibility is essential. You'll wear multiple hats, operate … solutions without needing handholding. Key Skills: Strong Python & Postgres experience are a must JavaScript & React proficiency would be valuable - but not essential as they have a dedicated React Developer API development & integration expertise Automation workflows We need a contractor who thrives in ambiguity, values simplicity in solutions, and can crack on with little oversight. If you're a More ❯

the Project Manager, architects, clients & other stakeholders to implement MuleSoft APIs. This role will require knowledge of MuleSoft's Anypoint Studio & Anypoint Platform, which includes Design Center, Runtime Manager, API Manager, Exchange, etc. You must be capable of understanding business requirements, working with stakeholders & implementing complex integrations. Responsibilities: Designing & developing integration solutions using MuleSoft Anypoint Platform. Building & maintaining integration … modules. Collaborating with other developers & stakeholders to understand business requirements & translate them into integration solutions. Required Skills: Good experience of: integration concepts & technologies. MuleSoft Anypoint Platform & components (Mule ESB, API Manager, CloudHub, etc.) Java programming & experience with other programming languages such as XML, JSON, SQL Agile software development methodologies. Cloud-based integration platforms such as Amazon Web Services … AWS) or Microsoft Azure. API design and development. Knowledge of RESTful web services, SOAP, & other integration protocols Familiarity with API design & development best practices Strong problem-solving skills & ability to troubleshoot integration issues. Good communication & teamwork skills Strong understanding of Agile development methodologies & experience working in an Agile environment Nice to Have Skills: Experience with cloud More ❯

AWS (Aurora, DMS, Lambda, Kinesis), Azure Data Factory Real-time Streaming: Apache Kafka, AWS Kinesis, change data capture (CDC) Vector Databases: Pinecone, Weaviate, or Chroma etc. with LangChain integration API Development: RESTful services, third-party integrations Production Systems: Enterprise-grade monitoring, error handling, cost optimisation Outside IR35 Fully Remote Immediate start 3-6 Month Contract Please send CV More ❯

intelligence, document processing, and risk management. Key Responsibilities: Architect & Implement: Design and deploy secure AI services from lab to production, ensuring they are scalable and compliant with industry standards. API Development: Create robust APIs for large language models (LLMs), retrieval-augmented generation (RAG) pipelines, agentic workflows, and document intelligence systems. Cybersecurity & Privacy: Integrate cybersecurity and data privacy controls More ❯

intelligence, document processing, and risk management. Key Responsibilities: Architect & Implement: Design and deploy secure AI services from lab to production, ensuring they are scalable and compliant with industry standards. API Development: Create robust APIs for large language models (LLMs), retrieval-augmented generation (RAG) pipelines, agentic workflows, and document intelligence systems. Cybersecurity & Privacy: Integrate cybersecurity and data privacy controls More ❯