73 api developer jobs found

Christopher Ali are seeking a Full Stack RoR Developer to add new functionality to an existing Ruby on Rails 7 application at both UI and API level. The contract will be fully remote, 3 months initially (possibility to extend) and paying £550 per day. This role will be outside IR35. Skills Needed : Extensive experience with Ruby on Rails Proven experience building and maintaining applications covering both the frontend and backend Using a test driven approach to test large complex applications Solid understanding of computer science fundamentals Experience with cloud deployment strategies using Kubernetes

Microsoft Teams App Developer / Microsoft 365 Solutions Developer Outside IR35 | Contract | Hybrid - High Wycombe Contract: Outside IR35 Location: Hybrid (High Wycombe - on-site as required) Start: ASAP Duration: Initial contract with extension potential The Opportunity We are looking for an experienced Microsoft Teams App Developer to deliver a custom real-time meeting, microphone, and voting system built directly into Microsoft Teams . This project replaces traditional dedicated conference and voting hardware with a modern, software-based solution. You'll be building both the delegate-facing Teams app used in live meetings and the administrative control systems used to manage speakers, microphones, and voting in real time. This is a specialist contract role requiring deep Microsoft Teams platform experience , real-time systems knowledge, and strong enterprise UX instincts. What You'll Be...

Senior Backend Engineer (NodeJS) – HubSpot Experience – Remote - £600 per day Outside IR35 Role Overview We are seeking a Senior Backend Engineer to join one of our established engineering teams. This role requires a highly capable, proactive senior developer who is confident taking ownership, making decisions, and collaborating across teams. You will work across two key areas — primarily extending and enhancing a Commercial Data platform, while also taking technical ownership of an existing HubSpot implementation that is now being developed and maintained in-house. Prior HubSpot experience is essential for this role. The position will be approximately 70% focused on backend platform development and 30% on leading HubSpot development and improvements, working closely with architecture and product stakeholders. Technology NodeJS, PostgreSQL, AWS, HubSpot (essential), API integrations The Project You’ll contribute to the continued evolution of a...

Role: Contract C# .NET Developer Domain: Commodities trading Day rate: £600-650/d (outside IR35) Location: London (hybrid - 3 days per week) Contract: 6 months (strong extension scope) X4 Technology are partnered with a well-backed commodity trading firm in London offering an exciting outside IR35 contract opportunity for an experienced C# .NET Developer . You'll play a key role in a major platform transformation of their trading platform, helping to evolve their Energy Trading & Risk Management (ETRM) landscape into a scalable, data-first, event-driven and microservices-based architecture. The successful candidate will have the opportunity to work across multiple platforms: developing Endur ETRM OpenComponents (for Gas and Power), building RESTful and gRPC APIs for Symphony ETRM (for Oil) and enhancing the core codebase of Planlogic EOS ETRM (for LNG), for which the firm has acquired the source code. This is a pivotal role where you'll reshape...

We’re looking for an experienced developer for a short term contract (min 3 months) in our Manchester office, to help manage, maintain and build upon our technical capabilities across 3 different brands. You’ll be a vital and core in helping to deliver critical business objectives often to tight deadlines. Please note - this is a Manchester based role and we are not considering remote applications. This role sits outside of IR35 and has rate of £200 per day. Your day-to-day duties would include: • Development and maintenance of our web applications, including the  APIs powering our systems. • Collaborating with product owners to delivery technical tasks. • Working closely with the PM and stakeholders in other departments to  ensure correct delivery of features and projects. • Fostering effective communication and collaboration between in-house  teams to ensure cohesive execution of the technology roadmap. The ideal candidate would be proficient and have...

🚨 Contract Node Developer🚨📍 1–2 days per week in Central London⏳ 3‑month contract💷 £450–£500 per day (Outside IR35)Opus is partnered with a consultancy who work with major blue‑chip clients on large‑scale, high‑impact digital programmes for a government client. They’re looking for a Node Developer with strong engineering fundamentals and excellent communication skills.You’ll be building modern, standards‑compliant, API‑first applications and helping clients improve the performance, scalability, and reliability of their digital platforms.What you’ll be doing🔹 Designing, building, and supporting scalable frontend products🔹 Transforming requirements, workflows & UX designs into clean UI🔹 Building integrations between systems and applications🔹 Writing high‑quality, well‑tested code🔹 Managing priorities, deadlines and deliverables🔹 Identifying and resolving technical issues across domains🔹 Working directly with clients to implement digital solutions🔹 Leading small project groups and...

Software Developer – 6 Month Initial Contract – Hybrid – Leicester – Outside IR35 VIQU have partnered with a leading organisation who are seeking a full-stack Software Developer with strong front-end experience to join their team on a contract basis. The successful Software Developer will work across front-end and back-end services to rebuild internal applications previously supported by a third-party, collaborating with UX and cross-functional teams in an agile environment. Key Responsibilities Rebuild and decouple bespoke services previously supplied by a third-party vendor. Develop front-end and back-end components for internal applications. Collaborate with UX teams to create user-facing interfaces. Design, develop, and maintain APIs and Azure cloud services. Participate in agile ceremonies and work closely with stakeholders throughout the project lifecycle. Key Skills & Experience Strong front-end development skills (HTML, CSS, Blazor,...

🚨 Contract Node Developer 🚨 📍 1–2 days per week in Central London ⏳ 3‑month contract 💷 £450–£500 per day (Outside IR35) Opus is partnered with a consultancy who work with major blue‑chip clients on large‑scale, high‑impact digital programmes for a government client. They’re looking for a Node Developer with strong engineering fundamentals and excellent communication skills. You’ll be building modern, standards‑compliant, API‑first applications and helping clients improve the performance, scalability, and reliability of their digital platforms. What you’ll be doing 🔹 Designing, building, and supporting scalable frontend products 🔹 Transforming requirements, workflows & UX designs into clean UI 🔹 Building integrations between systems and applications 🔹 Writing high‑quality, well‑tested code 🔹 Managing priorities, deadlines and deliverables 🔹 Identifying and resolving technical issues across domains 🔹 Working directly with clients to...

ASP.NET Azure Microsoft Stack Contract Remote UK Public Sector Projects   Overview We are looking for an experienced  Senior Full Stack .NET Developer  to join our rapidly growing team delivering Agile projects using the latest Microsoft technologies. Our work is primarily with  UK Public Sector organisations , building secure, scalable solutions that drive value, improve services, and enhance user engagement. The role has a strong focus on  ASP.NET, Azure , and the wider Microsoft ecosystem, including Power Platform. As a Senior Developer, you will act as  Technical Lead on some projects , while contributing as a hands-on team member on others. You will also play a key role in shaping and promoting  development standards and best practices  across the team.   Who We’re Looking For We’re looking for someone who combines strong technical capability with a genuine interest in improving Public...

SharePoint / Microsoft 365 Application Developer required by our market leading client in Bristol. This will be a 3 month initial contract, likely to extend and will sit Outside IR35. We are looking for an experienced SharePoint / Microsoft 365 Application Developer to support ongoing digital transformation projects. This is a hands-on role requiring strong technical expertise, problem-solving skills, and the ability to deliver independently in a fast-paced environment. Key Responsibilities: Design, develop, and maintain SharePoint Online sites, libraries, lists, and workflows. Build custom solutions using Power Apps, Power Automate, and PowerShell. Develop modern SharePoint components using SPFx (SharePoint Framework). Integrate Microsoft 365 services including Teams, OneDrive, Azure AD, and Exchange Online. Migrate content from legacy SharePoint or file systems into SharePoint Online. Create reusable templates, components, and governance-aligned solutions....

Software Developer - 6 Month Initial Contract - Hybrid - Leicester - Outside IR35 VIQU have partnered with a leading organisation who are seeking a full-stack Software Developer with strong Front End experience to join their team on a contract basis. The successful Software Developer will work across Front End and Back End services to rebuild internal applications previously supported by a third-party, collaborating with UX and cross-functional teams in an agile environment. Key Responsibilities Rebuild and decouple bespoke services previously supplied by a third-party vendor. Develop Front End and Back End components for internal applications. Collaborate with UX teams to create user-facing interfaces. Design, develop, and maintain APIs and Azure cloud services. Participate in agile ceremonies and work closely with stakeholders throughout the project life cycle. Key Skills & Experience Strong Front End development skills (HTML, CSS, Blazor, JavaScript)....

Full Stack Developer Glasgow - Hybrid Outside IR35 12 months a { text-decoration: none; color: #464feb; } tr th, tr td { border: 1px solid #e6e6e6; } tr th { background-color: #f5f5f5; } We're looking for an experienced Contract Full Stack Developer to join our client and help deliver high-quality, modern applications across web and mobile. Key Skills: Strong JavaScript / TypeScript experience ReactJS for web application development React Native for mobile app delivery Node.js for backend services GraphQL API design and integration AWS experience (useful, but not essential) What We're After: A hands-on developer who can hit the ground running, collaborate well with their team, and deliver clean, reliable code. If this sounds like the right role for you, then please get in touch with Christina Hall at

SharePoint / Microsoft 365 Application Developer required by our market leading client in Bristol. This will be a 3 month initial contract, likely to extend and will sit Outside IR35 . We are looking for an experienced SharePoint / Microsoft 365 Application Developer to support ongoing digital transformation projects. This is a hands-on role requiring strong technical expertise, problem-solving skills, and the ability to deliver independently in a fast-paced environment. Key Responsibilities: Design, develop, and maintain SharePoint Online sites, libraries, lists, and workflows. Build custom solutions using Power Apps, Power Automate, and PowerShell. Develop modern SharePoint components using SPFx (SharePoint Framework). Integrate Microsoft 365 services including Teams, OneDrive, Azure AD, and Exchange Online. Migrate content from legacy SharePoint or file systems into SharePoint Online. Create reusable templates, components, and...

TypeScript Developer - Outside IR35 - Fully Remote TypeScript Developer required on a 9-month contract by our client in Edinburgh. Your new role: TypeScript Developers are required for a 9-month contract with an established organisation in Edinburgh. Due to their success, they are redeveloping their main product to be implemented in a new region. As part of that, they are looking to onboard contract TypeScript Developers with strong backend API and AWS knowledge. As a TypeScript Developer in the Agile team, you'll work closely with the Engineers, Design, and Front End teams to develop the new platform's Back End. As a contractor within the team, you'll be expected to get up to speed quickly and contribute to the whole backend development process, from ideation to delivery. Tech Skill Set: ** TypeScript ** Node ** Terraform ** GraphQL ** AWS The Rate: For the right person, we have a day rate of £500 -...

Boomi Integration Engineer Remote Contract Outside IR35 Rate is DOE Role Summary We’re looking for a hands-on integration engineer to design, build, test, and support enterprise integrations using Boomi. You’ll work with business stakeholders and engineers to connect SaaS apps, on-prem systems, and data sources using APIs, event/file patterns, and integration best practices. Key Responsibilities Build and maintain Boomi processes (API, event, batch, and file-based integrations). Design integrations end-to-end: requirements → mapping → error handling → deployment → monitoring. Develop and publish APIs (REST/SOAP) with appropriate security (OAuth2, basic auth, certificates, IP restrictions). Implement data transformations (JSON/XML/CSV), mapping, validation, enrichment, and canonical models. Set up and manage Boomi runtime/Atoms (Atom, Molecule, Atom Cloud) and environments. Configure connectors (CRM/ERP/databases/SFTP/HTTP) and manage credentials securely....

Salary: £500 - 550 per day Reference: 117725 Full Stack Developer (.NET/React) – Contract - £550/day (.NET, C#, React, Azure, OAuth, Docker, Kubernetes) We’re working with an industry leading commerce client that are looking for a full stack engineer to join them as part of an ongoing transformation. The client has cancelled their contract with an offshoring partner and are looking to bring most of the engineering back to the UK. This role will be outside IR35 and will be fully remote – please note that candidates must be based in the UK. This will be a 12-month contract. Technical requirements – .NET 8 or above, C# (latest features) SQL with Dapper ORM Unit testing using XUnit OR NUnit, Moq, AutoFixture Azure managed services OpenSearch ASP.NET Core Web API with Controller-Service-Repository architecture RESTful API design and best practices Core Skills (Frontend) React Redux for state management Unit testing using Jest TypeScript RESTful API...

ASP.NET Azure Microsoft Stack Contract Remote UK Public Sector Projects Overview We are looking for an experienced Senior Full Stack .NET Developer to join our rapidly growing team delivering Agile projects using the latest Microsoft technologies. Our work is primarily with UK Public Sector organisations , building secure, scalable solutions that drive value, improve services, and enhance user engagement. The role has a strong focus on ASP.NET, Azure , and the wider Microsoft ecosystem, including Power Platform. As a Senior Developer, you will act as Technical Lead on some projects , while contributing as a hands-on team member on others. You will also play a key role in shaping and promoting development standards and best practices across the team. Who We’re Looking For We’re looking for someone who combines strong technical capability with a genuine interest in improving Public Sector services. You’ll be comfortable working in Agile...

Boomi Integration Engineer Remote Contract Outside IR35 Role Summary We’re looking for a hands-on integration engineer to design, build, test, and support enterprise integrations using Boomi. You’ll work with business stakeholders and engineers to connect SaaS apps, on-prem systems, and data sources using APIs, event/file patterns, and integration best practices. Key Responsibilities Build and maintain Boomi processes (API, event, batch, and file-based integrations). Design integrations end-to-end: requirements → mapping → error handling → deployment → monitoring. Develop and publish APIs (REST/SOAP) with appropriate security (OAuth2, basic auth, certificates, IP restrictions). Implement data transformations (JSON/XML/CSV), mapping, validation, enrichment, and canonical models. Set up and manage Boomi runtime/Atoms (Atom, Molecule, Atom Cloud) and environments. Configure connectors (CRM/ERP/databases/SFTP/HTTP) and manage credentials securely. Establish...

TypeScript Developer - Outside IR35 - Fully Remote TypeScript Developer required on a 9-month contract by our client in Edinburgh. Your new role: TypeScript Developers are required for a 9-month contract with an established organisation in Edinburgh. Due to their success, they are redeveloping their main product to be implemented in a new region. As part of that, they are looking to onboard contract TypeScript Developers with strong backend API and AWS knowledge. As a TypeScript Developer in the Agile team, you'll work closely with the Engineers, Design, and Front End teams to develop the new platform's Back End. As a contractor within the team, you'll be expected to get up to speed quickly and contribute to the whole backend development process, from ideation to delivery. Tech Skill Set: ** TypeScript ** Node ** Terraform ** GraphQL ** AWS The Rate: For the right person, we have a day rate of £500 - £550, depending on your experience and what you...

Full Stack Developer (.NET/React) - Contract - £550/day (.NET, C#, React, Azure, OAuth, Docker, Kubernetes) We're working with an industry leading commerce client that are looking for a full stack engineer to join them as part of an ongoing transformation. The client has cancelled their contract with an offshoring partner and are looking to bring most of the engineering back to the UK. This role will be outside IR35 and will be fully remote - please note that candidates must be based in the UK. This will be a 12-month contract. Technical requirements - - .NET 8 or above, C# (latest features) - SQL with Dapper ORM - Unit testing using XUnit OR NUnit, Moq, AutoFixture - Azure managed services - OpenSearch - ASP.NET Core Web API with Controller-Service-Repository architecture - RESTful API design and best practices Core Skills (Frontend) - React - Redux for state management - Unit testing using Jest - TypeScript - RESTful API consumption Core Skills (Backend) -...