Integration Developer C# .Net (SC Cleared)

Salary: £? - ? per year

Requirements:

• Experience designing and implementing integration solutions using C#, .NET, or similar programming languages
• Experience building RESTful APIs and backend services
• Experience with integration platforms such as Azure Logic Apps, Azure Data Factory, SSIS, or other middleware tools
• Experience with API tools such as Postman, Swagger, and API gateways
• Experience working with REST and/or SOAP APIs, including authentication, authorization, and secure data exchange
• Experience with data transformation between formats such as JSON, XML, and CSV
• Experience with unit, integration, and end-to-end testing of integration workflows and APIs
• Experience debugging issues using tools such as Fiddler, Postman, and application logs
• Experience documenting API contracts, integration configurations, and solution architecture
• Ability to collaborate with business stakeholders, IT teams, external partners, developers, data engineers, QA teams, and business analysts
• Ability to communicate technical designs, project updates, and roadblocks to technical and non-technical stakeholders
• Commitment to keeping up to date with integration frameworks, cloud technologies, and development best practices
• Preferred candidate from HM Revenue & Customs (HMRC), Department for Work and Pensions (DWP), Home Office, Ministry of Defence (MOD), Ministry of Justice (MOJ), HM Treasury, Department for Education (DfE), Department for Transport (DfT), Department of Health and Social Care (DHSC), Department for Environment, Food & Rural Affairs (DEFRA), Department for Science, Innovation & Technology (DSIT), or Foreign, Commonwealth & Development Office (FCDO)

Responsibilities:

• Collaborate with business stakeholders, IT teams, and external partners to gather integration requirements and define workflows
• Design data mappings, transformations, APIs, and message schemas to support secure and efficient data exchange between systems
• Design, develop, test, and deploy integration solutions
• Build RESTful APIs and backend services to support integration needs
• Configure connectors and implement error handling and retry mechanisms to ensure reliability and data integrity
• Orchestrate data flows and integrate diverse systems using integration platforms and middleware tools
• Build and maintain APIs, including REST and SOAP services
• Integrate internal and third-party APIs to support service-oriented and event-driven architecture across systems
• Implement data transformation logic between different formats and schemas
• Perform unit, integration, and end-to-end testing of integration workflows and APIs
• Debug issues and continuously improve performance and reliability through code refactoring and system tuning
• Document API contracts, integration configurations, and solution architecture
• Provide progress updates, technical summaries, and risk reports to stakeholders throughout the project lifecycle
• Work closely with software developers, data engineers, QA teams, and business analysts to align integration work with project goals
• Participate in knowledge-sharing sessions and contribute to continuous improvement of integration standards and code quality

Technologies:

• API
• Azure
• Backend
• C#
• Cloud
• Fiddler
• Support
• JSON
• Postman
• REST
• SOAP
• SSIS
• Swagger
• XML
• ASP.NET
• Flow

More:

We are seeking an Integration professional to support secure and efficient data exchange between systems. You will work across business and technical teams to design, build, test, and maintain integration solutions, APIs, and data flows. You will use tools and platforms such as Azure Logic Apps, Azure Data Factory, SSIS, Postman, Swagger, and API gateways, while contributing to documentation, reporting, collaboration, and continuous improvement. GCS is acting as an Employment Business in relation to this vacancy.

last updated 39 week of 2026