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Locations
4 API jobs in Chelmsford + 20 miles
361 exact matches jobs are outside your preferred location
LSEG is seeking a Senior Vulnerability Management Engineer to join our internal offensive security team with focus on driving closure of penetration testing findings. This role bridges offensive security and engineering by translating penetration test results into clear, actionable remediation guidance and partnering with application and platform teams to implement secure fixes. The successful candidate has a strong penetration testing or application security background, hands on remediation experience, and the ability to coordinate multiple collaborators to reduce risk at scale. This is a highly technical, delivery focused role with responsibility for both individual findings and systemic improvements. Key Responsibilities * Analyze and review penetration test reports to understand technical impact, exploitability, and business risk.
LSEG is seeking a Senior Vulnerability Management Engineer to join our internal offensive security team with focus on driving closure of penetration testing findings. This role bridges offensive security and engineering by translating penetration test results into clear, actionable remediation guidance and partnering with application and platform teams to implement secure fixes. The successful candidate has a strong penetration testing or application security background, hands on remediation experience, and the ability to coordinate multiple collaborators to reduce risk at scale. This is a highly technical, delivery focused role with responsibility for both individual findings and systemic improvements. Key Responsibilities * Analyze and review penetration test reports to understand technical impact, exploitability, and business risk.
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London, Bristol or Edinburgh - We are working with a leading energy technology company that has built a major intelligence platform used by global energy and automotive brands. Their work helps accelerate the shift to reliable and affordable clean energy. The business operates internationally and promotes a flexible, hybrid approach to work. The Role - The company is hiring a Machine Learning Engineer at Tech Lead level to join a central ML team supporting Product and Engineering groups. You will design and productionise ML, optimisation and GenAI solutions that sit at the core of their platform. Projects include forecasting, recommendation systems and classification tools. Key Responsibilities * Build ML and GenAI solutions in Python, using Databricks, Kafka and AWS * Deploy and maintain algorithms in a microservices environment
London, Bristol or Edinburgh - We are working with a leading energy technology company that has built a major intelligence platform used by global energy and automotive brands. Their work helps accelerate the shift to reliable and affordable clean energy. The business operates internationally and promotes a flexible, hybrid approach to work. The Role - The company is hiring a Machine Learning Engineer at Tech Lead level to join a central ML team supporting Product and Engineering groups. You will design and productionise ML, optimisation and GenAI solutions that sit at the core of their platform. Projects include forecasting, recommendation systems and classification tools. Key Responsibilities * Build ML and GenAI solutions in Python, using Databricks, Kafka and AWS * Deploy and maintain algorithms in a microservices environment
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We are looking for an experienced Appian Developer to support integration and automation initiatives within a leading financial services organisation. This role focuses on connecting systems, automating complex business processes, and improving operational efficiency. * Design, develop, and maintain Appian applications to support fraud and spam prevention workflows. * Build and manage system integrations (APIs, web services, and third-party platforms) * Automate business processes to improve accuracy, speed, and resilience. * Working with offshore teams to complete end-to-end delivery, from requirements gathering to deployment * Ensure solutions meet security, compliance, and performance standards expected in financial services. * Must have proven experience as an Appian Developer. * Must have a strong background in system integration, process automation and APIs.
We are looking for an experienced Appian Developer to support integration and automation initiatives within a leading financial services organisation. This role focuses on connecting systems, automating complex business processes, and improving operational efficiency. * Design, develop, and maintain Appian applications to support fraud and spam prevention workflows. * Build and manage system integrations (APIs, web services, and third-party platforms) * Automate business processes to improve accuracy, speed, and resilience. * Working with offshore teams to complete end-to-end delivery, from requirements gathering to deployment * Ensure solutions meet security, compliance, and performance standards expected in financial services. * Must have proven experience as an Appian Developer. * Must have a strong background in system integration, process automation and APIs.
LSEG (London Stock Exchange Group) is more than a diversified global financial markets infrastructure and data business. We are dedicated, open-access partners with a dedication to excellence in delivering the services our customers expect from us. With extensive experience, deep knowledge and worldwide presence across financial markets, we enable businesses and economies around the world to fund innovation, manage risk and create jobs. Its how weve contributed to supporting the financial stability and growth of communities and economies globally for more than 300 years. Through a comprehensive suite of trusted financial market infrastructure services and our open-access model we provide the flexibility, stability and trust that enable our customers to pursue their ambitions with confidence and clarity.
LSEG (London Stock Exchange Group) is more than a diversified global financial markets infrastructure and data business. We are dedicated, open-access partners with a dedication to excellence in delivering the services our customers expect from us. With extensive experience, deep knowledge and worldwide presence across financial markets, we enable businesses and economies around the world to fund innovation, manage risk and create jobs. Its how weve contributed to supporting the financial stability and growth of communities and economies globally for more than 300 years. Through a comprehensive suite of trusted financial market infrastructure services and our open-access model we provide the flexibility, stability and trust that enable our customers to pursue their ambitions with confidence and clarity.
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Strong expertise across API management, event-driven architecture, microservices, and hybrid cloud
Strong expertise across API management, event-driven architecture, microservices, and hybrid cloud
PREMIUM
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Solutions Architect - 2 Days Either London or Peterborough/Rest Remote
Solutions Architect - 2 Days Either London or Peterborough/Rest Remote
ZENZO DIGITAL LTD
City of London (EC1)
From £75,000 to £85,000 per annum + Bens
Kubernetes and API Design'
Kubernetes and API Design'
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Define and govern API-led connectivity and enterprise integration patterns * Deep understanding of MuleSoft architecture, integration patterns, and API-led design
Define and govern API-led connectivity and enterprise integration patterns * Deep understanding of MuleSoft architecture, integration patterns, and API-led design
FEATURED
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Along with this you should also have hands on experience with API testing tools (e.g., Postman, REST Assured) and performance tools (e.g., JMeter, Gatling).
Along with this you should also have hands on experience with API testing tools (e.g., Postman, REST Assured) and performance tools (e.g., JMeter, Gatling).
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The successful applicant will have comprehensive expertise in Microsoft Azure services, Web API, Azure App Service, .NET Core, and Visual Studio. * Design and implement scalable cloud solutions utilizing Azure App Service, Web API, and .NET Core. * Define architecture patterns for microservices, API management, and integration with enterprise systems. * Utilize Azure Functions, Azure Logic Apps, Azure API Management, and Azure Storage to develop robust applications. * Expertise in Microsoft Azure services, including App Service, Functions, API Management, Storage, and Networking. * Strong knowledge of .NET Core, Web API, C#, and Visual Studio.
The successful applicant will have comprehensive expertise in Microsoft Azure services, Web API, Azure App Service, .NET Core, and Visual Studio. * Design and implement scalable cloud solutions utilizing Azure App Service, Web API, and .NET Core. * Define architecture patterns for microservices, API management, and integration with enterprise systems. * Utilize Azure Functions, Azure Logic Apps, Azure API Management, and Azure Storage to develop robust applications. * Expertise in Microsoft Azure services, including App Service, Functions, API Management, Storage, and Networking. * Strong knowledge of .NET Core, Web API, C#, and Visual Studio.
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Full Stack Engineer Python TypeScript
Full Stack Engineer Python TypeScript
Client Server
St James, South West London (SW1), SW1A
£100000 - £120000 per annum + bonus + benefits
You have strong backend Python coding skills, including API development
You have strong backend Python coding skills, including API development
PREMIUM
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5+ years experience in working with the .NET framework, particularly with ASP.NET Core, React/React Native, C#, Web API * Experience developing REST API-driven mobile first web applications
5+ years experience in working with the .NET framework, particularly with ASP.NET Core, React/React Native, C#, Web API * Experience developing REST API-driven mobile first web applications
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Skilled in API development and microservices architecture
Skilled in API development and microservices architecture
The core tech stack is: Java 8+, Spring MVC, SpringBoot, REST API's and using build tools such as Maven/Gradle.
The core tech stack is: Java 8+, Spring MVC, SpringBoot, REST API's and using build tools such as Maven/Gradle.
Expertise in system and API design, scalability, and performance tuning
Expertise in system and API design, scalability, and performance tuning
Hands-on experience with API development and microservices architecture and end-to-end integrations * Hands-on experience with API development and microservices architecture * Knowledge of API Gateways and ISTIO, ability to diagnose and intercept failures in end-to-end communication
Hands-on experience with API development and microservices architecture and end-to-end integrations * Hands-on experience with API development and microservices architecture * Knowledge of API Gateways and ISTIO, ability to diagnose and intercept failures in end-to-end communication
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Senior Full Stack Engineer
Senior Full Stack Engineer
McGregor Boyall Associates Limited
City of London (EC1)
£80000 - £120000 per annum + bonus
Strong knowledge of system design principles, scalable architecture patterns, and API design.
Strong knowledge of system design principles, scalable architecture patterns, and API design.
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AWS: API gateway, RDS, Cloudfront, Cognito, Terraform, GitHub, GitFlow pipelines
AWS: API gateway, RDS, Cloudfront, Cognito, Terraform, GitHub, GitFlow pipelines
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Experience building maintainable and testable code bases, including API design and unit testing techniques
Experience building maintainable and testable code bases, including API design and unit testing techniques
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Experience with some of the technologies we make use of: Groovy, Python, AWS Serverless (API Gateway, Lambdas), XML, JSON, Open API, virtualisation in general and especially Docker and its eco system, Git, NoSQL products and concepts (Dynamo, column family, etc.)
Experience with some of the technologies we make use of: Groovy, Python, AWS Serverless (API Gateway, Lambdas), XML, JSON, Open API, virtualisation in general and especially Docker and its eco system, Git, NoSQL products and concepts (Dynamo, column family, etc.)
Build, fine-tune, and evaluate LLM-based Q&A models using frameworks like AWS Bedrock, Langchain, HuggingFace Transformers or OpenAI API.
Build, fine-tune, and evaluate LLM-based Q&A models using frameworks like AWS Bedrock, Langchain, HuggingFace Transformers or OpenAI API.
Deep knowledge of REST API design, scalability, fault tolerance, and performance optimization.
Deep knowledge of REST API design, scalability, fault tolerance, and performance optimization.
Microservices architecture, API-first approach, containerisation (Docker/Kubernetes), CI/CD pipelines * Knowledge of integration patterns, API gateways, and cloud-native deployments
Microservices architecture, API-first approach, containerisation (Docker/Kubernetes), CI/CD pipelines * Knowledge of integration patterns, API gateways, and cloud-native deployments
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API Development with C# ASP.Net Core
API Development with C# ASP.Net Core
NEW
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Data exchange and processing skills (e.g. ETL, ESB, API...)
Data exchange and processing skills (e.g. ETL, ESB, API...)
FEATURED
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Salesforce Marketing Cloud Engineer
Salesforce Marketing Cloud Engineer
Stackstudio Digital Ltd.
Paddington, West London (W2)
From £450 to £500 per day
Strong understanding and experience in SFMC API development.
Strong understanding and experience in SFMC API development.