Date posted
Commute time
Locations
Type of Company
Job types
Salaries
Locations
Locations
Salaries
Date posted
Type of Company
Job types
51 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.
NEWPREMIUM
)
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
NEWPREMIUM
)
Integration Architect
Integration Architect
Lynx Recruitment Limited
SW1W, South West London
From £85,000 to £100,000 per annum
Create high-level architectural assets, including API catalogues, application and connectivity models, guiding detailed design - Solid understanding of SOA, REST, and API management principles - Proficient with XSD, XML, XSLT, JSON, API
Create high-level architectural assets, including API catalogues, application and connectivity models, guiding detailed design - Solid understanding of SOA, REST, and API management principles - Proficient with XSD, XML, XSLT, JSON, API
NEW
)
Strong experience with API and event-driven architectures.
Strong experience with API and event-driven architectures.
NEWFEATURED
)
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.
NEW
Strong understanding of REST API design and backend microservices architecture
Strong understanding of REST API design and backend microservices architecture
NEW
)
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.
NEW
)
Oversee system enhancements and API integrations
Oversee system enhancements and API integrations
NEWFEATURED
)
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.)
NEW
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)
NEWFEATURED
)
ASP.NET Web API
ASP.NET Web API
NEW
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)
NEW
)
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
NEW
Exposure to OpenAI API or other modern AI/ML integrations.
Exposure to OpenAI API or other modern AI/ML integrations.
NEW
)
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
NEWFEATURED
)
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.
NEW
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.
NEW
)
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.
NEWPREMIUM
)
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.
NEW
)
Build and work with modern API and microservices architectures
Build and work with modern API and microservices architectures
NEWEQUALITY BOOST
)
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.
NEW
)
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)
NEW
)
Software Engineer - Scientific Instrumentation - London
Software Engineer - Scientific Instrumentation - London
Bond Williams Limited
W10, West London
Negotiable
A brand new vacancy for a Software Engineer with an incredible scientific instrumentation start-up has become available, based in West London (W12). The Software Engineer will form part of an interdisciplinary team developing software to automate laboratory equipment and processes. * Collaborate cross-functionally with scientists, engineers and bioinformaticians to streamline experimental workflows, improve user experience, and integrate software with complex hardware systems. * Develop and refine GUIs for prototype instruments working with stakeholders. * Develop and maintain embedded software or firmware for instruments where applicable. * Ensure robust communication between hardware components e.g., sensors, actuators, pumps. * Develop software to automate lab processes, sample handling, experimental protocols, and data collection.
A brand new vacancy for a Software Engineer with an incredible scientific instrumentation start-up has become available, based in West London (W12). The Software Engineer will form part of an interdisciplinary team developing software to automate laboratory equipment and processes. * Collaborate cross-functionally with scientists, engineers and bioinformaticians to streamline experimental workflows, improve user experience, and integrate software with complex hardware systems. * Develop and refine GUIs for prototype instruments working with stakeholders. * Develop and maintain embedded software or firmware for instruments where applicable. * Ensure robust communication between hardware components e.g., sensors, actuators, pumps. * Develop software to automate lab processes, sample handling, experimental protocols, and data collection.
NEW
Office Location: Hemel Hempstead - Hybrid Working - Salary: £70,000 - We are seeking a capable and business-savvyDynamics 365 CRM Product Managerto lead the strategy, design, and evolution of our CRM platform. This is a hybrid role that blends traditional product ownership responsibilities with deep platform expertiseincluding hands-on configuration, role management, and solution optimisation across the Dynamics 365 environment. You will act as the central point of contact for CRM functionality, ensuring alignment with business processes and championing continuous improvement through well-informed design and feature decisions. Product Ownership * Serve as the primary owner of the Dynamics 365 CRM product roadmap, prioritising features and enhancements in line with business goals. * Work closely with stakeholders across departments to understand process needs, pain poi
Office Location: Hemel Hempstead - Hybrid Working - Salary: £70,000 - We are seeking a capable and business-savvyDynamics 365 CRM Product Managerto lead the strategy, design, and evolution of our CRM platform. This is a hybrid role that blends traditional product ownership responsibilities with deep platform expertiseincluding hands-on configuration, role management, and solution optimisation across the Dynamics 365 environment. You will act as the central point of contact for CRM functionality, ensuring alignment with business processes and championing continuous improvement through well-informed design and feature decisions. Product Ownership * Serve as the primary owner of the Dynamics 365 CRM product roadmap, prioritising features and enhancements in line with business goals. * Work closely with stakeholders across departments to understand process needs, pain poi
NEW
)
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
NEW