API Developer

Our Team:

The API Developer designs, builds, and maintains the APIs that connect enterprise systems, digital products, and external partners. This is a hands-on engineering role responsible for producing well-designed, robust, scalable, secure, well-documented APIs that other teams can discover and reuse for communication between internal products, third-party platforms and client-facing applications.;;

The API platform is run both as an internal product and as a managed service. The API Developer works contract-first, publishing APIs to the enterprise catalogue and developer portal, and builds the reusable components, templates, and policies that raise the standard of every API delivered across the organisation.;;

Kong is the primary gateway, operating alongside Apigee, Azure API Management, and AWS API Gateway across a multi-cloud estate on Microsoft Azure and Amazon Web Services. The role therefore values transferable, gateway-agnostic API skills as highly as any single product.;;

Main responsibilities:

API Design and Development;;

• Design and build APIs contract-first using Open API/Swagger, applying enterprise design standards, naming conventions, and versioning policy.;;


• Develop synchronous and asynchronous APIs across REST, GraphQL, gRPC, and event-driven patterns documented with AsyncAPI.;;


• Build domain and experience APIs that expose business capabilities cleanly, abstracting the complexity of underlying systems.;;


• Develop reusable API components, policies, plugins, and templates that other teams consume as a starting point.;;

Gateway and Runtime Implementation;;

• Implement and configure API proxies, routes, plugins, and policies on Kong Gateway and Kong Konnect.;;


• Deploy and operate gateway components on Kubernetes using the Kong Ingress Controller and GitOps workflows.;;


• Implement traffic management including rate limiting, throttling, caching, retries, and circuit breaking.;;

Security and Access Control;;

• Implement robust authentication and authorization mechanisms (OAuth 2.0, OpenID Connect, JWT, mutual TLS, API keys patterns);;


• Ensure APIs comply with regulatory and data privacy requirements (GDPR, GxP where applicable);;


• Integrate with enterprise identity providers including Entra ID and Okta.;;


• Manage secrets and certificates through HashiCorp Vault, CyberArk, and cloud-native key services.;;

Quality, Testing, and Automation;;

• Build automated contract, functional, integration, security, and performance tests for every API.;;


• Maintain CI/CD pipelines for API delivery using GitHub Actions or Azure DevOps, including linting and specification validation.;;


• Integrate static analysis, dependency scanning, and SBOM generation using SonarQube, Snyk, and equivalent tooling.;;

Operations and Support;;

• Instrument APIs for observability using OpenTelemetry format.;;


• Contribute during incident response, root-cause analysis, and problem management for API services.;;


• Build proactive monitoring services relying on Predictive ML.;;


• Support consumers through onboarding, troubleshooting, and clear technical guidance.;;

Technical Craft and Engineering Practices;;

• Write clean, tested, peer-reviewed code managed in Git using trunk-based practices.;;


• Use AI-assisted engineering tools such as GitHub Copilot and Claude Code to accelerate development, test generation, and documentation, applying appropriate review and technical judgement.;;


• Favour reuse and shared components over bespoke, single-purpose implementations.;;

Collaboration and Ways of Working;;

• Work within an agile product team with a shared backlog and defined customers.;;


• Partner with integration engineers, application teams, and data teams to agree interfaces and contracts.;;


• Engage with Cybersecurity and Architecture teams to keep API patterns aligned with approved standards.;;

About you;;;;

Required;;

• Demonstrated capability in API or backend software engineering, typically gained across five to eight years of professional experience.;;


• Proficiency in at least one modern backend language: Python or Node.js and TypeScript are preferred, and Java with Spring Boot is equally welcome.;;


• Deep understanding of REST architectural principles and GraphQL query language;;


• Experience with relational and NoSQL databases and the ability to write optimized queries;;


• Strong contract-first API design experience with Open API, including versioning and backward compatibility.;;


• Hands-on experience with an API gateway or management platform such as Kong, Apigee, Azure API Management, or AWS API Gateway.;;


• Practical experience implementing OAuth2, OpenID Connect, and TLS-based API security.;;


• Working knowledge of containers, Kubernetes, and CI/CD pipelines.;;


• Sound debugging skills across application, network, and gateway layers.;;


• Clear written and verbal communication in English, including the ability to document APIs for other engineers.;;

Preferred;;

• Experience with GraphQL federation and gRPC or Protocol Buffers.;;


• Experience with Kafka, Solace, or another event streaming or brokering platform.;;


• Experience integrating enterprise systems such as SAP, Salesforce, Veeva, Workday, or ServiceNow.;;


• Experience with developer portals, API catalogues, or API productization for external partners.;;


• Experience delivering within a regulated environment (GxP or other), including awareness of data-protection obligations such as GDPR.;;


• Certifications such as Kong, AWS or Azure developer level, or Certified Kubernetes Application Developer.;;


• A bachelor's degree in computer science, engineering, information technology, or a related discipline.;;

Core Competencies;;

• Design-led thinking with strong attention to interface quality;;


• Consumer focus and empathy for the developers who use your APIs;;


• Security awareness embedded in everyday engineering decisions;;


• Bias toward reuse, standardization, and simplification;;


• Pragmatic problem-solving under production pressure;;


• Ownership and follow-through;;


• Continuous learning and adaptability;;

Measures of Success;;

• Increased reuse of published APIs and shared components;;


• Reduced lead time from API design to production availability;;


• Improved conformance to enterprise API design and security standards;;


• Complete, accurate, and current API documentation in the catalogue;;


• Improved API availability, latency, and error rates against service levels;;


• Faster consumer onboarding and reduced support effort per API;;


• Reduced number of undocumented, duplicate, or unmanaged endpoints;