5 of 5 Contract API Design Jobs in London

Boomi Architect

Hiring Organisation
Syntax Consultancy Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£500/day 500/day (Outside IR35)
. Start ASAP during Summer 2026. Key skills, experience + tasks will include: Boomi Solution Architect with a strong focus on Boomi/iPaaS, API Management, Event Streaming, integration architecture, governance + technical leadership. Integration Adoption & Project Onboarding - architecture engagement + onboarding of priority projects onto the strategic integration … platform (e.g. SDEC, S4H, DWIT). Production of project-specific integration designs aligned to approved iPaaS, API and Streaming patterns. Completion of architecture assurance reviews and design recommendations for onboarding projects. Support projects through technical discovery, design and implementation phases. Reusable Integration Asset Library: design ...

Integration Architect - Java, AWS, FS - OutsideIR35

Hiring Organisation
Sanderson Recruitment
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£550 - £600 per day + Outside IR35
connectivity across the clients core systems. Key Responsibilities: Own and evolve integration architecture aligned with enterprise standards Define and govern integration patterns across teams Design and deliver event-driven, API-first, and messaging solutions (NATS, REST) Lead end-to-end integration delivery, including hands-on development (Java/… Spring) Ensure scalable, cloud-native solutions on AWS Produce architecture artefacts (blueprints, contracts, ADRs) Guide teams on best practices, API governance, and event design Engage stakeholders and align cross-team integration efforts Primary Skills: Event-driven architecture and messaging systems (NATS, pub/sub, async patterns) API ...

Backend Developer (Azure)

Hiring Organisation
Amtis Professional Ltd
Location
London, Euston, United Kingdom
Employment Type
Contract
Contract Rate
£425 - £475/day OUTSIDE IR35
outside IR35. This is a hands-on role working on a mature Azure-based backend platform, with responsibility across the full software lifecycle - from design and development through to testing, deployment and production support. You’ll be working with C#, .NET, Azure Functions, Azure SQL, Azure Service Bus, Azure … API Management and Azure DevOps, contributing to a platform that supports connected patient services. This role is particularly suited to a developer who can hit the ground running, work independently and own technical delivery end-to-end without requiring day-to-day technical supervision. What You’ll Be Doing ...

S/4HANA - Coupa Integration Architect

Hiring Organisation
CBSbutler Holdings Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
Up to £558 per day + inside ir35
between Coupa and SAP S/4HANA. This is an opportunity to work on a high-profile global programme, owning integration architecture from initial design through to deployment, cutover and Hypercare. What you'll be doing: Designing and delivering Coupa SAP S/4HANA integrations across complex enterprise landscapes … Leading integration architecture, solution design and technical delivery Building and managing APIs including REST/JSON, OData, IDocs and BAPIs Supporting procurement process integrations covering: Supplier and Business Partner data Purchase Orders Goods Receipts Service Entry Sheets Invoices and payment status updates Master data synchronisation Working with integration platforms ...

Backend Kotlin Engineer

Hiring Organisation
Synergetic
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP Annual
engineering best practices What we're looking for: Solid experience developing Back End applications in Kotlin Good understanding of Back End architecture and API design Ability to work independently in a remote or hybrid environment Strong communication skills, especially important for remote collaboration ...