Date posted
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Locations
4 Contract API jobs in Chelmsford + 20 miles
279 exact matches jobs are outside your preferred location
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Skilled in building robust, optimized API endpoints.
Skilled in building robust, optimized API endpoints.
Applied AI Software Engineer - London (Hybrid) - AWS Partner
Applied AI Software Engineer - London (Hybrid) - AWS Partner
Transparent Technology
London
£75000 - £150000 per annum
As a Software Engineer first, you will have deep expertise in at least one programming language (Python, Node.js, Java, JavaScript, TypeScript, React) and proven experience in productionising GenAI solutions, including integrating LLMs, LangChain, OpenAI API, or Claude.
As a Software Engineer first, you will have deep expertise in at least one programming language (Python, Node.js, Java, JavaScript, TypeScript, React) and proven experience in productionising GenAI solutions, including integrating LLMs, LangChain, OpenAI API, or Claude.
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Applications Support Analyst / Engineer
Applications Support Analyst / Engineer
Kudos Partners
Datchet Common, Slough (SL3), SL3
£75,000 per annum plus 12% bonus - generous benefits package
API support and monitoring tools (e.g., SolarWinds, AzureAppInsights)
API support and monitoring tools (e.g., SolarWinds, AzureAppInsights)
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Hands-on understanding and experience with API testing * Ability to develop functional tests, which exercise the UI, API and DB layers
Hands-on understanding and experience with API testing * Ability to develop functional tests, which exercise the UI, API and DB layers
FEATURED
Build APIs using API-led connectivity and established integration patterns * Expertise in MuleSoft Anypoint Platform, Mule 4, and API-led architecture
Build APIs using API-led connectivity and established integration patterns * Expertise in MuleSoft Anypoint Platform, Mule 4, and API-led architecture
FEATURED
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Familiarity with microservices, API integration patterns and cloud concepts such as AWS.
Familiarity with microservices, API integration patterns and cloud concepts such as AWS.
Familiarity with microservices, API integration patterns and cloud concepts such as AWS.
Familiarity with microservices, API integration patterns and cloud concepts such as AWS.
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Design and implement Service-Oriented Architecture, API gateways, and scalable integration strategies. * Expert in JavaScript, API protocols, message queuing, and synchronising data across POS, WMS, CRM, and loyalty systems.
Design and implement Service-Oriented Architecture, API gateways, and scalable integration strategies. * Expert in JavaScript, API protocols, message queuing, and synchronising data across POS, WMS, CRM, and loyalty systems.
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Data Engineer
Data Engineer
McGregor Boyall Associates Limited
Turnham Green, West London (W4), W4 1SY
£30000 - £35000 per annum
Develop API integrations to connect multiple business systems
Develop API integrations to connect multiple business systems
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Excellent opportunity for an experienced .NET Backend Developer to join a rapidly growing business in London, where you will play a key role in shaping the backend systems, API architecture, and cloud infrastructure that support the company's technology roadmap.
Excellent opportunity for an experienced .NET Backend Developer to join a rapidly growing business in London, where you will play a key role in shaping the backend systems, API architecture, and cloud infrastructure that support the company's technology roadmap.
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Automation skills (PowerShell, Graph API) for identity lifecycle and migration tasks.
Automation skills (PowerShell, Graph API) for identity lifecycle and migration tasks.
Building reliable ELT/ETL processes, API integrations, and automated workflows (Workato).
Building reliable ELT/ETL processes, API integrations, and automated workflows (Workato).
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Senior Automated & Manual Tester – Mobile, Playwright, C#, SQL, Azure
Senior Automated & Manual Tester – Mobile, Playwright, C#, SQL, Azure
Smart Sourcer Limited
City of London (EC1)
From £70,000 to £75,000 per annum + 10% bonus + excellent benefits
Hands-on experience with Playwright or similar automation tools (e.g. Selenium) with extensive experience enhancing automated test frameworks for UI & API testing * Maintaining and enhancing UI/API test frameworks (e.g., Selenium, Playwright)
Hands-on experience with Playwright or similar automation tools (e.g. Selenium) with extensive experience enhancing automated test frameworks for UI & API testing * Maintaining and enhancing UI/API test frameworks (e.g., Selenium, Playwright)
Strong understanding of API integrations, RESTful services, and event streaming.
Strong understanding of API integrations, RESTful services, and event streaming.
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Front Office Developer - Technical Team Lead
Front Office Developer - Technical Team Lead
CMC Markets UK Plc
The City, City of London (EC3), EC3A 7BX
Competitive Salary + Bonus, Pension, Private Health, Life Assurance
Proven experience designing and developing API-based, microservices-driven architectures.
Proven experience designing and developing API-based, microservices-driven architectures.
FEATURED
Vitest/Jest, Docker, CI/CD (GitHub Actions), Shadcn/MUI, MongoDB, microservices, Cloudflare/CDNs, Firebase, Google Maps API, startup experience.
Vitest/Jest, Docker, CI/CD (GitHub Actions), Shadcn/MUI, MongoDB, microservices, Cloudflare/CDNs, Firebase, Google Maps API, startup experience.
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Principal Engineer
Principal Engineer
Kingston Barnes Engineering
Keeley Green, Bedford (MK42), MK42
£80,000 per annum holiday, pension, sick pay, life assurance
Familiarity with industry standards (ISO, API, HI) and experience testing and validating designs
Familiarity with industry standards (ISO, API, HI) and experience testing and validating designs
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Senior Full Stack Engineer React TypeScript
Senior Full Stack Engineer React TypeScript
Client Server
The City, City of London (EC4), EC2V
£80000 - £90000 per annum + benefits
You have strong React and Redux front end skills combined with backend JavaScript, TypeScript, Node.js and API experience
You have strong React and Redux front end skills combined with backend JavaScript, TypeScript, Node.js and API experience
PREMIUM
Supplier and partner API integrations (pricing, availability, constraints, factual data) * Translate commercial, operational and customer needs into clear product, API and data requirements * Partner with engineering to design and evolve API contracts, data structures and error handling * Proven experience as a Product Manager working on platform, API, data or pricing-heavy products
Supplier and partner API integrations (pricing, availability, constraints, factual data) * Translate commercial, operational and customer needs into clear product, API and data requirements * Partner with engineering to design and evolve API contracts, data structures and error handling * Proven experience as a Product Manager working on platform, API, data or pricing-heavy products
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Senior Software Developer Python (SC Cleared)
Senior Software Developer Python (SC Cleared)
Certes IT Service Solutions
London
£625 - £650 per day + Negotiable
Work within a multi-disciplinary product team and lead decisions on development and maintenance of a robust, scalable open data website (front end and back end); it's services and API's.
Work within a multi-disciplinary product team and lead decisions on development and maintenance of a robust, scalable open data website (front end and back end); it's services and API's.
Job Title:Solution Architect Finance - Mode of Working:Hybrid - Work Location (UK & I):Luton, UK - Role Description * Lead enterprise-level design discussions as a Finance Architect * Drive solution ideation, solution design, and solution implementation involving Finance, HR, and Procurement * Directly assist in the development of a solutions architecture program * Review enterprise architecture changes and validate against best-in-class industry standards * Direct the identification and recommendation of appropriate solutions, upgrades, replacements, or decommissioning options incorporating business and technology productivity, usability, and total cost of ownership (TCO) * Manage activities that take place during solution ideation, solution design, and solution implementation * Review business context for solutions to company challenges, design to realize the vision
Job Title:Solution Architect Finance - Mode of Working:Hybrid - Work Location (UK & I):Luton, UK - Role Description * Lead enterprise-level design discussions as a Finance Architect * Drive solution ideation, solution design, and solution implementation involving Finance, HR, and Procurement * Directly assist in the development of a solutions architecture program * Review enterprise architecture changes and validate against best-in-class industry standards * Direct the identification and recommendation of appropriate solutions, upgrades, replacements, or decommissioning options incorporating business and technology productivity, usability, and total cost of ownership (TCO) * Manage activities that take place during solution ideation, solution design, and solution implementation * Review business context for solutions to company challenges, design to realize the vision
Solution Architect
Solution Architect
McGregor Boyall Associates Limited
South West London (SW1)
£90000.00 - £120000.00 per annum
Solutions Architect £90,000 - £120,000 - Central London, 5 days onsite a week - Looking for candidates with experience of working within logistics, heavy industry or businesses with significant physical assets ! This logistics business, based in central London, has undertaken a significant change and transformation programme, the outcome of which is a new multi SAAS platform that will underpins the future state of the architecture. As part of this programme we are looking for a Solution Architect to contribute to shaping the future-state architecture that enables the organisation to meet its strategic business goals. This role ensures that technology solutions directly support desired business outcomes - such as improved efficiency, customer experience, scalability, and innovation-while maintaining strong architectural integrity.
Solutions Architect £90,000 - £120,000 - Central London, 5 days onsite a week - Looking for candidates with experience of working within logistics, heavy industry or businesses with significant physical assets ! This logistics business, based in central London, has undertaken a significant change and transformation programme, the outcome of which is a new multi SAAS platform that will underpins the future state of the architecture. As part of this programme we are looking for a Solution Architect to contribute to shaping the future-state architecture that enables the organisation to meet its strategic business goals. This role ensures that technology solutions directly support desired business outcomes - such as improved efficiency, customer experience, scalability, and innovation-while maintaining strong architectural integrity.
Maintain and administer DevOps toolchain components including Git, Artifactory, SonarQube, and API-based scripting solutions. Proficiency in Git, Artifactory, SonarQube, and API scripting.
Maintain and administer DevOps toolchain components including Git, Artifactory, SonarQube, and API-based scripting solutions. Proficiency in Git, Artifactory, SonarQube, and API scripting.
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Strong focus on optimizing inference performance and cost (e.g., model compression, quantization, API optimization).
Strong focus on optimizing inference performance and cost (e.g., model compression, quantization, API optimization).
FEATURED
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Secure-Linux tools & API libraries.
Secure-Linux tools & API libraries.