Date posted
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Locations
Type of Company
Job types
Salaries
Locations
Locations
Salaries
Date posted
Type of Company
Job types
Locations
40 Contract API jobs in Borehamwood + 20 miles
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A top-tier defense organization is looking for an experienced Axway API Developer / Administrator to join their team on a 6-month contract. * Axway's core products: Policy Studio, API Gateway, and API Manager. If you are an experienced professional with a background in API, MFT, or secure file transfers, this could be the perfect opportunity for you.
A top-tier defense organization is looking for an experienced Axway API Developer / Administrator to join their team on a 6-month contract. * Axway's core products: Policy Studio, API Gateway, and API Manager. If you are an experienced professional with a background in API, MFT, or secure file transfers, this could be the perfect opportunity for you.
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In this critical role, youll develop and maintain REST API over serverless functions using TypeScript; youll also design and implement scalable PostgreSQL schemas and data models. Other organisations may call this role Software Engineer, Software Developer, Back End Software Engineer, Server-Side Developer, Full Stack Developer, or API Developer.
In this critical role, youll develop and maintain REST API over serverless functions using TypeScript; youll also design and implement scalable PostgreSQL schemas and data models. Other organisations may call this role Software Engineer, Software Developer, Back End Software Engineer, Server-Side Developer, Full Stack Developer, or API Developer.
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Utilise Fetch API to automate interactions with web services and validate data flows.
Utilise Fetch API to automate interactions with web services and validate data flows.
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API integrations
API integrations
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Strong grasp of databases (SQL/NoSQL) and API integrations
Strong grasp of databases (SQL/NoSQL) and API integrations
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Knowledge of ServiceNow scripting (JavaScript, Glide API) a plus.
Knowledge of ServiceNow scripting (JavaScript, Glide API) a plus.
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Optimize inference performance and cost (e.g., model compression, quantization, API optimization).
Optimize inference performance and cost (e.g., model compression, quantization, API optimization).
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.NET Developer
.NET Developer
Halian Technology Limited
W1, Central London
From £70,000 to £80,000 per annum Plus bonus and benefits
Proven hands-on experience withAWS servicessuch as Lambda, ECS/Fargate, API Gateway, DynamoDB, S3, CloudFormation/Terraform.
Proven hands-on experience withAWS servicessuch as Lambda, ECS/Fargate, API Gateway, DynamoDB, S3, CloudFormation/Terraform.
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API Integration (OData ideally)
API Integration (OData ideally)
Strong background in software architecture, microservices, and API design.
Strong background in software architecture, microservices, and API design.
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Digital and Web Analyst
Digital and Web Analyst
iQ Student Accommodation Astor House
SE1, South East London, SE1 2DB
£55k - 60k per year + 25 days annual leave (plus bank holidays)
Familiarity with conversion APIs (Meta CAPI, Google Enhanced Conversions, TikTok Events API)
Familiarity with conversion APIs (Meta CAPI, Google Enhanced Conversions, TikTok Events API)
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Solutions Architect - 6 months £700 per day - 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. The Solution Architect oversees the design of systems and applications across the enterprise and regularly reviews the application portfolio to maximise value, reduce complexity, and ensure agility.
Solutions Architect - 6 months £700 per day - 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. The Solution Architect oversees the design of systems and applications across the enterprise and regularly reviews the application portfolio to maximise value, reduce complexity, and ensure agility.
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Build and work with modern API and microservices architectures
Build and work with modern API and microservices architectures
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Head of Development - AI Intelligence Platform. Remote UK
Head of Development - AI Intelligence Platform. Remote UK
Recruitment Revolution
EC2A, City of London
Competitive Salary + 20% bonus + Equity
Shape the platform architecture, ensuring scalable, secure, cloud-native design across AI, data, and API layers.
Shape the platform architecture, ensuring scalable, secure, cloud-native design across AI, data, and API layers.
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Senior Backend Engineer (Application & AI Orchestration)
Senior Backend Engineer (Application & AI Orchestration)
Ventula Consulting Limited
EC1, City of London
Up to £160,000 per annum
API & Application Development * Partner closely with the Senior Android Engineers to define robust API contracts and ensure a seamless, low-latency experience for the live transcript and mid-call intervention features.
API & Application Development * Partner closely with the Senior Android Engineers to define robust API contracts and ensure a seamless, low-latency experience for the live transcript and mid-call intervention features.
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Senior Backend Engineer - Platform Security
Senior Backend Engineer - Platform Security
Ventula Consulting Limited
EC1, City of London
Up to £160,000 per annum
We are seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. * Own and buildthe Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. * Ensureall network API integrations meet the stringent P99 latency budgets (e.g., < 150ms) required to support our sub-500ms Time-to-Trust product goal. * Collaboratewith the platform team to build a parallel development path using mocked data to mitigate risks of network API delays. * Deep understanding of API design(REST, gRPC, Webhooks) and API security (OAuth 2.0, mTLS, JWTs).
We are seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. * Own and buildthe Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. * Ensureall network API integrations meet the stringent P99 latency budgets (e.g., < 150ms) required to support our sub-500ms Time-to-Trust product goal. * Collaboratewith the platform team to build a parallel development path using mocked data to mitigate risks of network API delays. * Deep understanding of API design(REST, gRPC, Webhooks) and API security (OAuth 2.0, mTLS, JWTs).
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API & Application Development * Partner closely with the Senior Android Engineers to define robust API contracts and ensure a seamless, low-latency experience for the live transcript and mid-call intervention features.
API & Application Development * Partner closely with the Senior Android Engineers to define robust API contracts and ensure a seamless, low-latency experience for the live transcript and mid-call intervention features.
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Senior Technical Business Analyst
Senior Technical Business Analyst
REC SOLUTIONS LIMITED
The City, EC4
Competitive base salary plus bonus and benefits
Technical documentation Produce and maintain detailed technical and functional documentation, including API specifications, configuration workflows, and integration guides. * Proven ability to produce and maintain high-quality technical documentation and API specifications suitable for both engineering and client consumption.
Technical documentation Produce and maintain detailed technical and functional documentation, including API specifications, configuration workflows, and integration guides. * Proven ability to produce and maintain high-quality technical documentation and API specifications suitable for both engineering and client consumption.
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Principal Software Engineer - Unified Client Experience (UCX)
Principal Software Engineer - Unified Client Experience (UCX)
Hargreaves Lansdown
EC1, City of London
£11500 - £90000 per annum + Generous bonus, pension, PMI & more
Deep expertise in React or React Native, with hands-on experience in secure API integration, authentication flows, and frontend architecture.
Deep expertise in React or React Native, with hands-on experience in secure API integration, authentication flows, and frontend architecture.
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Software Engineering Manager - Unified Client Experience (UCX)
Software Engineering Manager - Unified Client Experience (UCX)
Hargreaves Lansdown
EC1, City of London
£90000 - £115000 per annum + Generous bonus, pension, PMI and more
Strong understanding of secure API integration, authentication flows, and modern UI/UX architecture.
Strong understanding of secure API integration, authentication flows, and modern UI/UX architecture.
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SeniorPower Platform developer
SeniorPower Platform developer
Halian Technology Limited
W1, Central London
From £70,000 to £85,000 per annum Plus bonus and benefits
My client is an award-winning and market-leading insights and solutions provider across pensions and financial services, energy, health, and analytics. The Opportunity - We're looking for an experienced and innovativePower Platform Developerto join my clients growing team. Youll play a key role in designing, developing, and supporting scalable, user-friendly business applications, automation workflows, and analytics solutions using Microsoft Power Platform. This is a fantastic opportunity to work across a diverse range of business areas, collaborating closely with stakeholders to drive digital transformation and operational efficiency. Key Responsibilities * Design, build, and maintain custom business applications usingPower Apps * Develop and enhance workflows and automations withPower Automate * Create interactive dashboards and data visualisations usingPower BI
My client is an award-winning and market-leading insights and solutions provider across pensions and financial services, energy, health, and analytics. The Opportunity - We're looking for an experienced and innovativePower Platform Developerto join my clients growing team. Youll play a key role in designing, developing, and supporting scalable, user-friendly business applications, automation workflows, and analytics solutions using Microsoft Power Platform. This is a fantastic opportunity to work across a diverse range of business areas, collaborating closely with stakeholders to drive digital transformation and operational efficiency. Key Responsibilities * Design, build, and maintain custom business applications usingPower Apps * Develop and enhance workflows and automations withPower Automate * Create interactive dashboards and data visualisations usingPower BI
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12 months - Remote - Inside IR35 - Umbrella only - Active SC clearance required - As a Salesforce Developer, you will lead the development of custom solutions on the Salesforce platform. You will be responsible for writing Apex code, creating visual force pages, and implementing integrations. You will have a strong understanding of the Salesforce platform and experience leading successful projects. A Senior Salesforce Developer will have a deep understanding of the Salesforce platform and the ability to develop complex solutions, mentor and lead the development team, troubleshoot and provide technical support to clients. They will also have a solid understanding of web development concepts and languages and keep up-to-date with new Salesforce features and best practices. * Skilled in Apex, HTML, JavaScript (ES6+), CSS, SLDS, and Salesforce DX.
12 months - Remote - Inside IR35 - Umbrella only - Active SC clearance required - As a Salesforce Developer, you will lead the development of custom solutions on the Salesforce platform. You will be responsible for writing Apex code, creating visual force pages, and implementing integrations. You will have a strong understanding of the Salesforce platform and experience leading successful projects. A Senior Salesforce Developer will have a deep understanding of the Salesforce platform and the ability to develop complex solutions, mentor and lead the development team, troubleshoot and provide technical support to clients. They will also have a solid understanding of web development concepts and languages and keep up-to-date with new Salesforce features and best practices. * Skilled in Apex, HTML, JavaScript (ES6+), CSS, SLDS, and Salesforce DX.
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We are looking for an enthusiastic and proactive Automation Tester with Python and Pytest experience to join our fantastic fintech client, largely remote with get togethers once a month in central London! This Automation Tester will be backend-focused, testing the server-side components, ensuring that the database (SQL), APIs, and business logic function correctly and efficiently. * Backend Automation testing skills with Python and Pytest. * Solid SQL skills and experience with relational databases. * Solid experience in automation testing using tools such as Selenium, Java, PHP, Go, or similar technologies. * Experience with Postman, SOAP UI, and Cucumber. * Batch processing experience. * Financial services / fintech experience. If you're passionate about testing, automation, and continuous learning, we would love to hear from you!
We are looking for an enthusiastic and proactive Automation Tester with Python and Pytest experience to join our fantastic fintech client, largely remote with get togethers once a month in central London! This Automation Tester will be backend-focused, testing the server-side components, ensuring that the database (SQL), APIs, and business logic function correctly and efficiently. * Backend Automation testing skills with Python and Pytest. * Solid SQL skills and experience with relational databases. * Solid experience in automation testing using tools such as Selenium, Java, PHP, Go, or similar technologies. * Experience with Postman, SOAP UI, and Cucumber. * Batch processing experience. * Financial services / fintech experience. If you're passionate about testing, automation, and continuous learning, we would love to hear from you!
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Front End Engineer React - Hedge Fund
Front End Engineer React - Hedge Fund
Client Server
Victoria, SW1
£80000 - £95000 per annum + bonus + benefits
Front End Engineer / Developer (React v19 TypeScript) London / WFH to £95k - Are you a Front End technologist looking for an opportunity to progress your career in a hands-on role with lots of learning opportunities? You could be joining a Hedge Fund with complex work and substantial bonus earning potential. As a Front End Engineer you'll join a globally distributed team to develop engaging and simple user interfaces across all internal business systems. You'll collaborate with UX and Product teams, actively participating in all stages of a project, through product design, development, implementation, testing and maintenance. You'll join colleagues in the impressive Central London office with flexibility to work from home twice a week. * You have strong Front End development skills with React (they're using v19) and TypeScript
Front End Engineer / Developer (React v19 TypeScript) London / WFH to £95k - Are you a Front End technologist looking for an opportunity to progress your career in a hands-on role with lots of learning opportunities? You could be joining a Hedge Fund with complex work and substantial bonus earning potential. As a Front End Engineer you'll join a globally distributed team to develop engaging and simple user interfaces across all internal business systems. You'll collaborate with UX and Product teams, actively participating in all stages of a project, through product design, development, implementation, testing and maintenance. You'll join colleagues in the impressive Central London office with flexibility to work from home twice a week. * You have strong Front End development skills with React (they're using v19) and TypeScript
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Senior Back End Developer TypeScript Node.js
Senior Back End Developer TypeScript Node.js
Client Server
EC2A, City of London
£65000 - £80000 per annum + benefits
Senior Back End Developer / Engineer (TypeScript Node.js) Remote UK to £80k - Are you a senior, hands-on Back End Developer looking for an opportunity to take ownership and progress your career at a scaling tech company? You could be joining a growing games company that combines state of the art technology, gaming and luxury fashion. As a Senior Back End Developer you'll join the team as they scale the product to support millions of users. You'll design and deliver high-quality, maintainable backend code and features using TypeScript and Node.js that is aligned with established codebase architectural standards and covered by tests as well as supporting backend system performance and reliability, helping to maintain 99% uptime SLA. You'll design, implement and extend robust APIs and microservices supporting gameplay, user management, platform and content management sys
Senior Back End Developer / Engineer (TypeScript Node.js) Remote UK to £80k - Are you a senior, hands-on Back End Developer looking for an opportunity to take ownership and progress your career at a scaling tech company? You could be joining a growing games company that combines state of the art technology, gaming and luxury fashion. As a Senior Back End Developer you'll join the team as they scale the product to support millions of users. You'll design and deliver high-quality, maintainable backend code and features using TypeScript and Node.js that is aligned with established codebase architectural standards and covered by tests as well as supporting backend system performance and reliability, helping to maintain 99% uptime SLA. You'll design, implement and extend robust APIs and microservices supporting gameplay, user management, platform and content management sys
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