Date posted
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Job types
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Locations
Locations
Salaries
Date posted
Type of Company
Job types
50 Permanent API jobs in Hertfordshire + 20 miles
Senior JavaScript Engineer / Developer (Vue.js API) London to £100k - Apply now to find out more about this Senior JavaScript Engineer / Developer (JavaScript Vue.js API) opportunity.
Senior JavaScript Engineer / Developer (Vue.js API) London to £100k - Apply now to find out more about this Senior JavaScript Engineer / Developer (JavaScript Vue.js API) opportunity.
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Backend Software Engineer Java Kotlin AWS
Backend Software Engineer Java Kotlin AWS
Client Server
Shoreditch, EC2A 2AP
£100000 - £120000 per annum
Backend Software Engineer / Developer (Java Kotlin AWS API) Hybrid WFH to £110k
Backend Software Engineer / Developer (Java Kotlin AWS API) Hybrid WFH to £110k
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Develop and manage API integrations between cloud-based and on-premise platforms - You'll be key to driving forward a cloud-first, API-driven approach to IT across the business.
Develop and manage API integrations between cloud-based and on-premise platforms - You'll be key to driving forward a cloud-first, API-driven approach to IT across the business.
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Strong experience with API and event-driven architectures.
Strong experience with API and event-driven architectures.
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Build and maintain an API used by the product as well as external partners.
Build and maintain an API used by the product as well as external partners.
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Strong understanding of REST API design and backend microservices architecture
Strong understanding of REST API design and backend microservices architecture
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Investran Application Specialist
Investran Application Specialist
Cobalt Recruitment.
City of London, London
£75000.00 - £95000 per annum
Proven track record of configuring and integrating financial platforms, ideally with SQL and API experience.
Proven track record of configuring and integrating financial platforms, ideally with SQL and API experience.
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Senior Software Engineer
Senior Software Engineer
Halian Technology Limited
W1, Central London
From £90,000 to £95,000 per annum Plus bonus and benefits
Cloud experience withAWSservices (Lambda, API Gateway, S3, etc.)
Cloud experience withAWSservices (Lambda, API Gateway, S3, etc.)
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They're after a Principal Infrastructure Engineer who’s as comfortable scripting against an API as they are deep-diving into Nutanix clusters. * Automate everything – Terraform, PowerShell, Python, REST APIs (Nutanix CLI/API experience a big plus)
They're after a Principal Infrastructure Engineer who’s as comfortable scripting against an API as they are deep-diving into Nutanix clusters. * Automate everything – Terraform, PowerShell, Python, REST APIs (Nutanix CLI/API experience a big plus)
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Perform Dataverse customizations, SQL queries, and CRUD operations using REST/Web API calls. * JavaScript (customizations & API calls)
Perform Dataverse customizations, SQL queries, and CRUD operations using REST/Web API calls. * JavaScript (customizations & API calls)
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Exposure to OpenAI API or other modern AI/ML integrations.
Exposure to OpenAI API or other modern AI/ML integrations.
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Proficiency in at least one major API testing framework - Experience withAzure (APIM, Azure Functions, API Services), React/React-Native and.NET Core
Proficiency in at least one major API testing framework - Experience withAzure (APIM, Azure Functions, API Services), React/React-Native and.NET Core
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Are you a hands-on Lead or Senior .Net Developer ready to shape architecture and guide talented developers? Want a hybrid role with 3 days WFH? This is your chance to stay close to the code while making key technical decisions that drive real business impact. You'll join a collaborative, forward-thinking team building cutting-edge products — with the support, tools, and flexibility to thrive. Role: Lead Software Developer, Senior .Net Developer, Software Engineering Manager, Senior Full Stack Developer, Lead .Net Developer, Lead Software Engineer, Senior C# Developer - Salary: £65k - £75k base + Bonus - Benefits: 5% pension, 25 days holiday, 2 wellbeing days, Christmas shutdown, private healthcare, life assurance, cinema tickets & more - Location: Milton Keynes – Hybrid (2 days a week in office) If you’ve got strong .Net (C#) experience and skills in GitHub, APIs, Pos
Are you a hands-on Lead or Senior .Net Developer ready to shape architecture and guide talented developers? Want a hybrid role with 3 days WFH? This is your chance to stay close to the code while making key technical decisions that drive real business impact. You'll join a collaborative, forward-thinking team building cutting-edge products — with the support, tools, and flexibility to thrive. Role: Lead Software Developer, Senior .Net Developer, Software Engineering Manager, Senior Full Stack Developer, Lead .Net Developer, Lead Software Engineer, Senior C# Developer - Salary: £65k - £75k base + Bonus - Benefits: 5% pension, 25 days holiday, 2 wellbeing days, Christmas shutdown, private healthcare, life assurance, cinema tickets & more - Location: Milton Keynes – Hybrid (2 days a week in office) If you’ve got strong .Net (C#) experience and skills in GitHub, APIs, Pos
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Software Developer (Microsoft Stack)
Software Developer (Microsoft Stack)
Solus Accident Repair Centres
North London, London
GBP £35,000.00/Yr. - GBP £50,000.00/Yr.
Work across a wide range of technologies, across web, mobile apps, API, backend, and databases which are currently hosted within Azure.
Work across a wide range of technologies, across web, mobile apps, API, backend, and databases which are currently hosted within Azure.
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Software Developer-MS-Stack
Software Developer-MS-Stack
Solus Accident Repair Centres
North London, London
GBP £35,000.00/Yr. - GBP £50,000.00/Yr.
Work across a wide range of technologies, across web, mobile apps, API, backend, and databases which are currently hosted within Azure.
Work across a wide range of technologies, across web, mobile apps, API, backend, and databases which are currently hosted within Azure.
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Global Claims IT Leader
Global Claims IT Leader
MARSH CORPORATE SERVICES LIMITED
The City, EC3R 5BU
Pension Scheme, Private Health Insurance & life insurance
Being a cross-functional collaborator interfacing with MMC Enterprise Technology partners, Marsh-Operations, and Transformation Office will come naturally to you building a new set of reusable IT Microservices connected via a well-defined API structure.
Being a cross-functional collaborator interfacing with MMC Enterprise Technology partners, Marsh-Operations, and Transformation Office will come naturally to you building a new set of reusable IT Microservices connected via a well-defined API structure.
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Take a lead role in the development and support ofMicrosoft MVC and .NET web applications and C# Console and API solutions, ensuring best practices are followed throughout the software lifecycle. * Proficient in.NET (C#), JavaScript, Web API, SQL Server, and working knowledge ofHTML, CSS, XML, JSON.
Take a lead role in the development and support ofMicrosoft MVC and .NET web applications and C# Console and API solutions, ensuring best practices are followed throughout the software lifecycle. * Proficient in.NET (C#), JavaScript, Web API, SQL Server, and working knowledge ofHTML, CSS, XML, JSON.
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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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Good understanding of API integration and data flow between front-end and back-end.
Good understanding of API integration and data flow between front-end and back-end.
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Principal Software Engineer (Cloud Applications)
Principal Software Engineer (Cloud Applications)
Eckoh PLC
HP1, Hemel Hempstead
Up to £100000 per annum
Build cloud-native applications using AWS services such as Lambda, API Gateway, DynamoDB, SQS, and EventBridge * Solid experience with AWS application services (Lambda, API Gateway, Step Functions, DynamoDB, etc.) * Proven ability to design and build modern, API-driven systems in a scalable resilient cloud-based platform * Experience with modern front-end frameworks and API integration (React, Vue, Angular)
Build cloud-native applications using AWS services such as Lambda, API Gateway, DynamoDB, SQS, and EventBridge * Solid experience with AWS application services (Lambda, API Gateway, Step Functions, DynamoDB, etc.) * Proven ability to design and build modern, API-driven systems in a scalable resilient cloud-based platform * Experience with modern front-end frameworks and API integration (React, Vue, Angular)
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Senior Software Developer
Senior Software Developer
Lean People Services Limited
Luton, Bedfordshire
From £75,000 to £85,000 per annum
up to £85,000 per annum - Full Time Mon-Fri - Our Client provide remote diagnostic solutions and services to the automotive industry. They offer cutting-edge, expert diagnostics using both after-market and original equipment manufacturer tools to provide safe and accurate repairs. The company was founded in 2010 and is headquartered in Plano, TX with UK offices in Peterlee and Bedfordshire. As more automotive software technologies emerge, including autonomous driving, advanced diagnostics, vehicle connectivity, digital cockpits the Company aims to gain a first-mover advantage by developing software solutions with the help of automotive software engineers. If the idea of making an impact on a project lifecycle sounds appealing from its inception down to testing and deployment appeals to you, keep on reading!
up to £85,000 per annum - Full Time Mon-Fri - Our Client provide remote diagnostic solutions and services to the automotive industry. They offer cutting-edge, expert diagnostics using both after-market and original equipment manufacturer tools to provide safe and accurate repairs. The company was founded in 2010 and is headquartered in Plano, TX with UK offices in Peterlee and Bedfordshire. As more automotive software technologies emerge, including autonomous driving, advanced diagnostics, vehicle connectivity, digital cockpits the Company aims to gain a first-mover advantage by developing software solutions with the help of automotive software engineers. If the idea of making an impact on a project lifecycle sounds appealing from its inception down to testing and deployment appeals to you, keep on reading!
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A growing B2B FinTech is looking for a Senior Backend Engineer to help reshape its platform for scale. Youll join a collaborative engineering team delivering secure, high-performance APIs and backend services that power global business payments. What Youll Do * Build and maintain clean, well-tested APIs and services in C#/.NET * Contribute to a modular, microservices-based architecture * Work across the stack with engineers, QA, DevOps, and Product * Lead on code quality, performance, and engineering best practices * Support a shift toward better automation, monitoring, and CI/CD - Tech Snapshot * .NET Core / C# / EF Core * SQL Server, RESTful APIs, DDD patterns * Azure, Docker, CI/CD pipelines * Messaging with NServiceBus or similar * TDD, Git, modern SDLC practices - What Were Looking For * Strong backend experience in C#/.NET
A growing B2B FinTech is looking for a Senior Backend Engineer to help reshape its platform for scale. Youll join a collaborative engineering team delivering secure, high-performance APIs and backend services that power global business payments. What Youll Do * Build and maintain clean, well-tested APIs and services in C#/.NET * Contribute to a modular, microservices-based architecture * Work across the stack with engineers, QA, DevOps, and Product * Lead on code quality, performance, and engineering best practices * Support a shift toward better automation, monitoring, and CI/CD - Tech Snapshot * .NET Core / C# / EF Core * SQL Server, RESTful APIs, DDD patterns * Azure, Docker, CI/CD pipelines * Messaging with NServiceBus or similar * TDD, Git, modern SDLC practices - What Were Looking For * Strong backend experience in C#/.NET
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About the Company - You'll be joining a global leader in real estate services and technology solutions. Known for combining deep market expertise with cutting-edge innovation, this business is committed to modernising how property and investment decisions are made. You'll be part of a collaborative, forward-thinking environment that values creativity, accountability, and growth-where your contributions will directly shape the future of real estate technology. Role Responsibilities * Architect, build, and optimise scalable ETL pipelines for diverse datasets. * Onboard, document, and curate external datasets for internal use. * Perform data validation, forensic analysis, and troubleshooting. * Deliver high-quality, maintainable Python code and participate in peer reviews. * Collaborate with stakeholders and researchers to support analytics and product development.
About the Company - You'll be joining a global leader in real estate services and technology solutions. Known for combining deep market expertise with cutting-edge innovation, this business is committed to modernising how property and investment decisions are made. You'll be part of a collaborative, forward-thinking environment that values creativity, accountability, and growth-where your contributions will directly shape the future of real estate technology. Role Responsibilities * Architect, build, and optimise scalable ETL pipelines for diverse datasets. * Onboard, document, and curate external datasets for internal use. * Perform data validation, forensic analysis, and troubleshooting. * Deliver high-quality, maintainable Python code and participate in peer reviews. * Collaborate with stakeholders and researchers to support analytics and product development.
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Senior React Developer / Front End Engineer (React TypeScript Data Visualisation) London to £80k - Are you a skilled Software Developer with strong React and Data Visualisation skills combined with a good appreciation of financial markets and technology? You could be joining a growing, global, Fintech services company that has seen 30-40% year on year growth for the past 10 years and has ambitious growth plans. As a Senior React Developer you'll design and develop new features and enhancements to the front end of the platform with a focus on real-time data visualisation on business critical systems using React. You'll collaborate with backend engineers to build complex financial products. You'll join the team in Central London three days a week with flexibility to work from home the other two days.
Senior React Developer / Front End Engineer (React TypeScript Data Visualisation) London to £80k - Are you a skilled Software Developer with strong React and Data Visualisation skills combined with a good appreciation of financial markets and technology? You could be joining a growing, global, Fintech services company that has seen 30-40% year on year growth for the past 10 years and has ambitious growth plans. As a Senior React Developer you'll design and develop new features and enhancements to the front end of the platform with a focus on real-time data visualisation on business critical systems using React. You'll collaborate with backend engineers to build complex financial products. You'll join the team in Central London three days a week with flexibility to work from home the other two days.
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iOS Mobile Engineer
iOS Mobile Engineer
Queen Square Recruitment Limited
W1, Central London
From £70,000 to £90,000 per annum
Were looking for a talented iOS Mobile Engineer to join our growing team in London, working 4 days per week on cutting-edge mobile products that integrate with AI and modern APIs. In this role, youll play a key part in designing, developing, and maintaining robust iOS applications, while collaborating with designers, backend engineers, and AI specialists. Youll thrive if youre excited about modern mobile architecture, seamless user experiences, and the intersection of AI and mobile. What Youll Do * Design, build, and maintain iOS apps using Swift, following best practices from both the client and OEMs * Collaborate on UI/UX design, DevOps workflow, and priority features with the wider team * Participate in code reviews, and help resolve bugs, changes, and feedback efficiently * Integrate RESTful APIs with backend teams to deliver seamless mobile functionality
Were looking for a talented iOS Mobile Engineer to join our growing team in London, working 4 days per week on cutting-edge mobile products that integrate with AI and modern APIs. In this role, youll play a key part in designing, developing, and maintaining robust iOS applications, while collaborating with designers, backend engineers, and AI specialists. Youll thrive if youre excited about modern mobile architecture, seamless user experiences, and the intersection of AI and mobile. What Youll Do * Design, build, and maintain iOS apps using Swift, following best practices from both the client and OEMs * Collaborate on UI/UX design, DevOps workflow, and priority features with the wider team * Participate in code reviews, and help resolve bugs, changes, and feedback efficiently * Integrate RESTful APIs with backend teams to deliver seamless mobile functionality
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