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98 Permanent API jobs in Holborn, Central London + 20 miles
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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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Forward Deployed Engineer
Forward Deployed Engineer
McGregor Boyall Associates Limited
EC1, City of London
£70000 - £90000 per annum
Strong data modelling, pipeline development, and API design experience.
Strong data modelling, pipeline development, and API design experience.
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API Development:Experience building data-centric APIs, especially withFastAPIon serverless platforms likeGoogle App Engine.
API Development:Experience building data-centric APIs, especially withFastAPIon serverless platforms likeGoogle App Engine.
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Strong foundation in web development, REST API design, and secure best practices
Strong foundation in web development, REST API design, and secure best practices
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Implement and maintain API integrations
Implement and maintain API integrations
Experience with RESTful API design and integration.
Experience with RESTful API design and integration.
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Experience with RESTful API design and integration.
Experience with RESTful API design and integration.
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Senior Solution Architect
Senior Solution Architect
UK Health Security Agency
Canary Wharf, E14 4PU
From £54,416 to £68,344 per annum
The United Kingdom Health Security Agency (UKHSA) is a system leader for health security; taking action internationally to strengthen global health security, providing trusted advice to government and the public and reducing inequalities in the way different communities experience and are impacted by infectious disease, environmental hazards, and other threats to health. UKHSAs remit, as an agency with a global-to-local reach, is to protect the health of the nation from infectious diseases and other external threats to health. * Prevent: anticipate threats to health and help build the nations readiness, defences and health security * Detect: use cutting edge environmental and biological surveillance to proactively detect and monitor infectious diseases and threats to health * Analyse: use world-class science and data analytics to assess and continually monitor threats
The United Kingdom Health Security Agency (UKHSA) is a system leader for health security; taking action internationally to strengthen global health security, providing trusted advice to government and the public and reducing inequalities in the way different communities experience and are impacted by infectious disease, environmental hazards, and other threats to health. UKHSAs remit, as an agency with a global-to-local reach, is to protect the health of the nation from infectious diseases and other external threats to health. * Prevent: anticipate threats to health and help build the nations readiness, defences and health security * Detect: use cutting edge environmental and biological surveillance to proactively detect and monitor infectious diseases and threats to health * Analyse: use world-class science and data analytics to assess and continually monitor threats
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Global Claims, IT Solutions Leader
Global Claims, IT Solutions Leader
MARSH CORPORATE SERVICES LIMITED
The City, EC3R 5BU
Discretionary Bonus, Pension Scheme & Private Healthcare
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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Student Systems Developer
Student Systems Developer
London School of Science & Technology Ltd T/a LSST
Park Royal, W3 0XA
Unspecified
Authentication & Integration Services API integrations, SSO (Single Sign-On), and system interoperability with University IT infrastructure.
Authentication & Integration Services API integrations, SSO (Single Sign-On), and system interoperability with University IT infrastructure.
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Familiarity with Endur and the .NET API (Open Components) is a plus.
Familiarity with Endur and the .NET API (Open Components) is a plus.
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This role will focus on building scalable, innovative solutions within Salesforce Marketing Cloud and Salesforce Core Platform, including the development of custom journey activities, API integrations, and bespoke applications that enhance our marketing automation and CRM capabilities. * 5+ years of experience in Salesforce Marketing Cloud development, with a strong focus on custom journey activities and API integrations.
This role will focus on building scalable, innovative solutions within Salesforce Marketing Cloud and Salesforce Core Platform, including the development of custom journey activities, API integrations, and bespoke applications that enhance our marketing automation and CRM capabilities. * 5+ years of experience in Salesforce Marketing Cloud development, with a strong focus on custom journey activities and API integrations.
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Experience in working with and ingesting a variety of different data sources of different data types (e.g. JSON, CSV, API etc.)
Experience in working with and ingesting a variety of different data sources of different data types (e.g. JSON, CSV, API etc.)
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Location: Esher (two days WFH) Must have Right to Work in the UK (cannot provide sponsorship) This person will contribute directly to the organisations digital transformation roadmap by embedding automation and AI into our operations and business. This will involve building AI-powered conversational agents and automating business processes using Microsoft Power Platform tools like Power Apps, Power Automate, and Power Virtual Agents (part of Microsoft Copilot Studio). * Chatbot Development: Design, build, and implement AI chatbots using Power Virtual Agents/Copilot Studio to streamline interactions and automate tasks. * Process Automation: Create automated workflows and processes using Power Automate to improve efficiency and reduce manual tasks, often incorporating AI capabilities. * Application Development: Develop intelligent business applications with Power Apps,
Location: Esher (two days WFH) Must have Right to Work in the UK (cannot provide sponsorship) This person will contribute directly to the organisations digital transformation roadmap by embedding automation and AI into our operations and business. This will involve building AI-powered conversational agents and automating business processes using Microsoft Power Platform tools like Power Apps, Power Automate, and Power Virtual Agents (part of Microsoft Copilot Studio). * Chatbot Development: Design, build, and implement AI chatbots using Power Virtual Agents/Copilot Studio to streamline interactions and automate tasks. * Process Automation: Create automated workflows and processes using Power Automate to improve efficiency and reduce manual tasks, often incorporating AI capabilities. * Application Development: Develop intelligent business applications with Power Apps,
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Full Stack Engineer TypeScript
Full Stack Engineer TypeScript
Client Server
South Kensington, SW7
£65000 - £75000 per annum + benefits
Full Stack Engineer / Developer (TypeScript) London to £75k - Opportunity to progress your career at a Tech for Good company that is enabling life changing education to be accessed by students around the world. As a Full Stack Engineer you will design and develop large, distributed, scalable web based systems, working within a modern cloud (AWS) microservices based environment; you'll be primarily using Typescript and Node for backend development, but will also have exposure to React on the frontend. You'll work across multiple teams and product streams in a collaborative environment that values code quality. The company are passionate about providing excellent education to hundreds of thousands of students around the world and support a number of causes and cutting edge research projects that improve the way people learn via real-time, live streaming technology as we
Full Stack Engineer / Developer (TypeScript) London to £75k - Opportunity to progress your career at a Tech for Good company that is enabling life changing education to be accessed by students around the world. As a Full Stack Engineer you will design and develop large, distributed, scalable web based systems, working within a modern cloud (AWS) microservices based environment; you'll be primarily using Typescript and Node for backend development, but will also have exposure to React on the frontend. You'll work across multiple teams and product streams in a collaborative environment that values code quality. The company are passionate about providing excellent education to hundreds of thousands of students around the world and support a number of causes and cutting edge research projects that improve the way people learn via real-time, live streaming technology as we
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Role: Full Stack Software Engineer (UK-based, early-stage startup) £60,000 - £80,000 per annum | No Sponsorship | x3 week in office - Backed by technology start up accelerator and VC - Join a mission-driven AI startup transforming how medical and healthcare organisations collaborate. Using machine learning and advanced recommendation systems, the team helps to matchmake some of the leading Medical and Pharmaceuticalbusinesses with their extensive network of professionals. This allows them to engage seamlessly all while reducing operational costs so resources can focus on changing lives. This is the chance to work on cutting-edge AI technology at an early stage with real influence on product and architecture to help medical organisations do more with their resources while changing lives and impact clients across the US and FTSE markets.
Role: Full Stack Software Engineer (UK-based, early-stage startup) £60,000 - £80,000 per annum | No Sponsorship | x3 week in office - Backed by technology start up accelerator and VC - Join a mission-driven AI startup transforming how medical and healthcare organisations collaborate. Using machine learning and advanced recommendation systems, the team helps to matchmake some of the leading Medical and Pharmaceuticalbusinesses with their extensive network of professionals. This allows them to engage seamlessly all while reducing operational costs so resources can focus on changing lives. This is the chance to work on cutting-edge AI technology at an early stage with real influence on product and architecture to help medical organisations do more with their resources while changing lives and impact clients across the US and FTSE markets.
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JavaScript Developer - Hybrid Remote
JavaScript Developer - Hybrid Remote
VERTECH GROUP (UK) LTD
N7, North London
From £80,000 to £100,000 per annum + Benefits
JavaScript Developer - Location: 3-4 days per wk from home / 1-2 days in London - Salary: Circa 80k 100k + Benefits - JavaScript Developer required byrequired by fast-growing, revolutionary tech company! This is a varied, challenging role in a talented team where youll be responsible for developing scalable backend services that bring their AI vision to life. You dont need to be a machine learning researcher but you do need to know how to integrate modern AI capabilities into productions * At least 4 years backend development experience * Solid expertise in Node.js * Experience integrating LLM APIs and open-source models into production systems * Hands-on work implementing Retrieval-Augmented Generation (RAG) pipelines * Experience designing and optimizing agentic AI workflows - Tremendous opportunity offering plenty of scope for career progression in a friendly, inno
JavaScript Developer - Location: 3-4 days per wk from home / 1-2 days in London - Salary: Circa 80k 100k + Benefits - JavaScript Developer required byrequired by fast-growing, revolutionary tech company! This is a varied, challenging role in a talented team where youll be responsible for developing scalable backend services that bring their AI vision to life. You dont need to be a machine learning researcher but you do need to know how to integrate modern AI capabilities into productions * At least 4 years backend development experience * Solid expertise in Node.js * Experience integrating LLM APIs and open-source models into production systems * Hands-on work implementing Retrieval-Augmented Generation (RAG) pipelines * Experience designing and optimizing agentic AI workflows - Tremendous opportunity offering plenty of scope for career progression in a friendly, inno
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Backend Engineer - Scale Systems with Real Impact ?? Tired of tinkering at the edges? Want to actually shape the backbone of a platform that's transforming how the world's biggest enterprises run their tech? This is one of those rare roles where you get in early, build the foundations, and watch your work scale across global businesses. We're working with a high-growth London startup on a mission to reinvent enterprise software. Their AI-driven platform is already saving household-name customers millions in IT costs, shaving months off ERP project timelines, and making sense of the mess that legacy systems leave behind. SAP is just the beginning - they're building a whole new category of Enterprise System Intelligence. The Role * Build core systems capable of handling tens of millions of lines of code and large-scale LLM workloads.
Backend Engineer - Scale Systems with Real Impact ?? Tired of tinkering at the edges? Want to actually shape the backbone of a platform that's transforming how the world's biggest enterprises run their tech? This is one of those rare roles where you get in early, build the foundations, and watch your work scale across global businesses. We're working with a high-growth London startup on a mission to reinvent enterprise software. Their AI-driven platform is already saving household-name customers millions in IT costs, shaving months off ERP project timelines, and making sense of the mess that legacy systems leave behind. SAP is just the beginning - they're building a whole new category of Enterprise System Intelligence. The Role * Build core systems capable of handling tens of millions of lines of code and large-scale LLM workloads.
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Senior Java Software Engineer
Senior Java Software Engineer
Run-Time Group Ltd
SW19, South West London
From £70,000 to £85,000 per annum
Job Title: Mid-Senior Java Engineer - Location:London (Hybrid - 2-3 days in-office) Salary:Up to £85,000 per annum + Benefits - Sector:Financial Services - We are seeking aSenior-Level Java Engineerto join a dynamic financial technology team in London. You will play a key role in developing, maintaining, and enhancing high-performance, scalable financial applications. This is a fantastic opportunity for an ambitious developer with experience in Java and a passion for the financial sector. The role follows a hybrid working model, with 2-3 days per week in the office. * Design, develop, and maintain high-quality Java-based applications for financial services. * Collaborate with cross-functional teams to deliver robust and scalable software solutions. * Ensure code quality, security, and performance standards are met.
Job Title: Mid-Senior Java Engineer - Location:London (Hybrid - 2-3 days in-office) Salary:Up to £85,000 per annum + Benefits - Sector:Financial Services - We are seeking aSenior-Level Java Engineerto join a dynamic financial technology team in London. You will play a key role in developing, maintaining, and enhancing high-performance, scalable financial applications. This is a fantastic opportunity for an ambitious developer with experience in Java and a passion for the financial sector. The role follows a hybrid working model, with 2-3 days per week in the office. * Design, develop, and maintain high-quality Java-based applications for financial services. * Collaborate with cross-functional teams to deliver robust and scalable software solutions. * Ensure code quality, security, and performance standards are met.
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Java Quantitative Developer Low Latency
Java Quantitative Developer Low Latency
James Joseph Associates Limited
EC2N, City of London
From £150,000 to £175,000 per annum Circa 50-100% Bonus + Pension + Be
Our client is a leading and well-established player in the Digital Asset and Cryptocurrency Quantitative/Algorithmic trading industry. The business is going from strength to strength, they are currently going through a period of exponential growth and are enjoying record profits The business is actively expanding as there is additional headcount for a number trade platform specialist Java Development with a focus on either/or Quantitative Development or low-latency performance optimization. You will be working on greenfield projects to build out and enhance their low latency trading systems. Working in a fast-paced trading environment as a Quant Developer, where you will collaborate closely with expert traders, quantitative analysts, and engineering specialists to craft and fine-tune trading strategies across both spot and derivative markets.
Our client is a leading and well-established player in the Digital Asset and Cryptocurrency Quantitative/Algorithmic trading industry. The business is going from strength to strength, they are currently going through a period of exponential growth and are enjoying record profits The business is actively expanding as there is additional headcount for a number trade platform specialist Java Development with a focus on either/or Quantitative Development or low-latency performance optimization. You will be working on greenfield projects to build out and enhance their low latency trading systems. Working in a fast-paced trading environment as a Quant Developer, where you will collaborate closely with expert traders, quantitative analysts, and engineering specialists to craft and fine-tune trading strategies across both spot and derivative markets.
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Senior Data Scientist / Engineer
Senior Data Scientist / Engineer
Serve Legal
Pimlico, SW1
From £60,000 to £75,000 per annum plus 10% company bonus scheme
Reports to: Data Director / Executive Sponsor - Location: Remote with occasional travel to London (2 times a month) Contract: Full-time, permanent - Base Salary: £60,000 £75,000 dependent on location and experience + 10% bonus scheme - Why This Role Exists - Serve Legal is forging new ground: transforming operational data into market-ready products, algorithms, and insights that redefine client value. As a driver of our Innovation Labs, you will experiment, prototype, and build compelling data solutions in a startup-within-a-business environmentboldly iterating and owning proofs-of-concept that scale. This is a position with a balance between data science and engineering. Besides exploring and analysing datasets, you will help to establish a cloud native data foundations, with a data warehouse and supporting data pipelines.
Reports to: Data Director / Executive Sponsor - Location: Remote with occasional travel to London (2 times a month) Contract: Full-time, permanent - Base Salary: £60,000 £75,000 dependent on location and experience + 10% bonus scheme - Why This Role Exists - Serve Legal is forging new ground: transforming operational data into market-ready products, algorithms, and insights that redefine client value. As a driver of our Innovation Labs, you will experiment, prototype, and build compelling data solutions in a startup-within-a-business environmentboldly iterating and owning proofs-of-concept that scale. This is a position with a balance between data science and engineering. Besides exploring and analysing datasets, you will help to establish a cloud native data foundations, with a data warehouse and supporting data pipelines.
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Espire Infolabs is hiring for MS Power Platform Engineer for London, UK location. Job Title: MS Power Platform Engineer - Job Type: Permanent - Job Location: London (3 Days/week onsite) We are seeking a skilled Power Platform Engineer with deep insurance industry expertise to design, develop, and implement automation solutions using Microsoft Power Platform technologies. The successful candidate will serve as a technical expert in Power Automate and broader Power Platform capabilities while effectively managing stakeholder relationships and driving digital transformation initiatives within the insurance and re-insurance domain. Key Responsibilities - Technical Development * Design and develop complex automation workflows using Power Automate (formerly Microsoft Flow) * Microsoft Copilot Studio * Build custom applications using Power Apps to meet specific business requ
Espire Infolabs is hiring for MS Power Platform Engineer for London, UK location. Job Title: MS Power Platform Engineer - Job Type: Permanent - Job Location: London (3 Days/week onsite) We are seeking a skilled Power Platform Engineer with deep insurance industry expertise to design, develop, and implement automation solutions using Microsoft Power Platform technologies. The successful candidate will serve as a technical expert in Power Automate and broader Power Platform capabilities while effectively managing stakeholder relationships and driving digital transformation initiatives within the insurance and re-insurance domain. Key Responsibilities - Technical Development * Design and develop complex automation workflows using Power Automate (formerly Microsoft Flow) * Microsoft Copilot Studio * Build custom applications using Power Apps to meet specific business requ
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Senior Backend Software Engineer (Python)
Senior Backend Software Engineer (Python)
Plexus Resource Solutions Ltd
EC1A, City of London
From £90,000 to £120,000 per annum
Web3 - London, England £90-£120K - Plexus are working with a company that are building the future of gaming by introducing equitable ownership and compensation models powered by blockchain. Through our suite of Web3 games and DAO-driven products, we create opportunities for players worldwide to share in the value they help create. As a Senior Backend Engineer, youll play a key role in shaping the infrastructure behind Web3 products. From crafting Python-based APIs to building seamless blockchain integrations, youll help power a platform that brings decentralized ownership to the next generation of gaming - Responsibilities * Architect and develop backend systems to power Web3 applications * Build and deploy RESTful APIs using Python * Connect backend services with Web3 protocols, blockchains, DAOs, and smart contracts - What we're looking for
Web3 - London, England £90-£120K - Plexus are working with a company that are building the future of gaming by introducing equitable ownership and compensation models powered by blockchain. Through our suite of Web3 games and DAO-driven products, we create opportunities for players worldwide to share in the value they help create. As a Senior Backend Engineer, youll play a key role in shaping the infrastructure behind Web3 products. From crafting Python-based APIs to building seamless blockchain integrations, youll help power a platform that brings decentralized ownership to the next generation of gaming - Responsibilities * Architect and develop backend systems to power Web3 applications * Build and deploy RESTful APIs using Python * Connect backend services with Web3 protocols, blockchains, DAOs, and smart contracts - What we're looking for
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This is a fantastic opportunity to work as a contract SuiteCRM Developer on a remote contract, inside IR35. This SuiteCRM Developer will be asked to deliver customisation, integration, and ongoing support for their CRM platform. * SuiteCRM or SugarCRM * PHP * CRM databases * Git * APIs If you do have the relevant experience for this contract SuiteCRM Developer position, please do apply.
This is a fantastic opportunity to work as a contract SuiteCRM Developer on a remote contract, inside IR35. This SuiteCRM Developer will be asked to deliver customisation, integration, and ongoing support for their CRM platform. * SuiteCRM or SugarCRM * PHP * CRM databases * Git * APIs If you do have the relevant experience for this contract SuiteCRM Developer position, please do apply.
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Backend Engineer Python
Backend Engineer Python
Plexus Resource Solutions Ltd
EC1, City of London
From £90,000 to £120,000 per annum
Backend Engineer - On-Chain Social Network - Remote £90k £120k - Plexus are working with an on-chain social network that empowers people to express themselves, connect with others, and explore the value of imagination. To support our growth and deliver a world-class experience, were looking for a Backend Engineer to join our core product team. Responsibilities * Work closely with the team to design, build, and deliver new product features * Develop and maintain the APIs that power our platform * Contribute to system reliability by taking part in our on-call rotation - Requirements * Solid experience with Python, GraphQL, and MongoDB * Flexibility to move across the stack when needed * Hands-on experience in blockchain development * Strong product intuition with a focus on user experience - Benefits * Competitive salary * Top-quality medical, dental & vision insurance
Backend Engineer - On-Chain Social Network - Remote £90k £120k - Plexus are working with an on-chain social network that empowers people to express themselves, connect with others, and explore the value of imagination. To support our growth and deliver a world-class experience, were looking for a Backend Engineer to join our core product team. Responsibilities * Work closely with the team to design, build, and deliver new product features * Develop and maintain the APIs that power our platform * Contribute to system reliability by taking part in our on-call rotation - Requirements * Solid experience with Python, GraphQL, and MongoDB * Flexibility to move across the stack when needed * Hands-on experience in blockchain development * Strong product intuition with a focus on user experience - Benefits * Competitive salary * Top-quality medical, dental & vision insurance
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