API Integration Lead

Software Development Engineer in Test (SDET) - Integration & Mediator Services

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AXA UK Commercial Claims | Guidewire SaaS Migration Programme

About the Role

We are migrating AXA UK's commercial claims handling from a legacy on-premise Guidewire system onto Guidewire ClaimCenter SaaS. A critical part of this programme is the design and build of a new mediator service layer, approximately 40 discrete integration services connecting Guidewire SaaS to the external systems that underpin commercial claims handling: repair networks, payment rails, regulatory portals, fraud databases, document management, broker channels, and more.

You will be the first dedicated SDET embedded in the integration engineering team, working across the full test lifecycle from strategy through to execution. Your primary focus will be ensuring the correctness, resilience, and performance of complex API-based mediator services before they are consumed by a System Integrator partner building out new commercial claims functionality from 2027.

The integrations you will test range from simple synchronous reference lookups through to high-complexity, regulation-critical workflows with mandatory SLA obligations and automatic legal consequences on failure. This is a hands-on engineering role. You will write, own, and maintain automated test suites, not manage others who do.

Testing is a shared engineering responsibility in this team. The developer engineers write tests alongside their code, and you will work with them as a peer, setting the framework, standards, and patterns that everyone codes to, reviewing each other's test coverage, and collectively owning quality. Your role is to raise the ceiling on what the team can achieve in testing, particularly in the specialist areas of automation architecture, NFR testing, and test data; not to be a separate QA gate at the end of a handoff.

Key Responsibilities

Collaboration and Quality

Work closely with engineers during development shift-left, pairing on testability, reviewing API specs and data contracts before build begins

• Raise and track defects with sufficient detail (reproduction steps, environment, payload examples) to enable rapid diagnosis
• Contribute to and review test plans for each integration
• Support the Guidewire SME and BA team in validating that mediator service behaviour correctly reflects the business rules of each integration
• Preparation of Test Closure Reports (TCRs)

API Test Automation

• With reference to the integration testing standards, setup the test framework in the team
• Design, build, and maintain an automated API test suite covering Experience, Process, and System layer mediator services using a three-tier architecture
• Write functional tests covering happy paths, unhappy paths, error conditions, retry behaviour, idempotency, and edge cases for each integration
• Develop contract tests to validate that mediator service interfaces conform to agreed API specifications and that upstream/downstream systems honour their contracts
• Integrate test suites into the CI/CD pipeline so that every build is validated automatically
• Work within AXA's agreed tooling standards to establish automation patterns and test quality standards for the team
• Use AI coding and test generation tools to accelerate test authoring including generating test cases, edge case scenarios, boundary conditions and synthetic test data from API contracts and OpenAPI/Swagger specifications
• Stay current with emerging AI-assisted testing practices and contribute to evolving how the team uses these tools effectively within AXA's standards

NFR and Performance Testing

• Define, document, and execute non-functional test scenarios covering: latency SLAs, throughput under load, availability behaviour, graceful degradation, circuit breaker and timeout handling, and retry/back-off logic
• Build and maintain JMeter performance test plans for each integration, with particular focus on high-volume integrations and those with regulation-critical SLA obligations
• Conduct soak testing, spike testing, and stress testing to validate behaviour under peak load conditions (e.g. post-storm events generating simultaneous commercial property claims)
• Establish baseline performance metrics and track regressions across builds

Test Data Management

• Design and own a test data strategy for a complex integration landscape spanning PII-sensitive insurance data, regulatory datasets, and third-party system simulators
• Build and maintain synthetic test datasets that represent the full range of claim types: motor, property, casualty, and fleet liability
• Create and manage stubs, mocks, and service virtualisations for third-party systems that cannot be tested directly in lower environments
• Ensure test data lifecycle management meets AXA standards and is GDPR-compliant
• Manage test data seeding and teardown as part of automated test execution

Integration-Specific Testing

• Test unhappy paths and failure modes explicitly, including timeout handling, dead-letter queue behaviour, duplicate/idempotency scenarios, partial responses, and compensating transactions
• Validate error handling end-to-end: that errors are correctly classified, surfaced, logged, and queued
• Test regulatory-critical integrations with particular rigour: certain integrations carry automatic legal consequences on failure and require bulletproof test coverage including simulated downstream unavailability and SLA breach scenarios

Required Skills and Experience

• Demonstrable experience testing integrations between multiple systems not just single-application testing
• Strong understanding of integration failure modes: timeouts, retries, idempotency, dead letters, compensating transactions
• Ability to read and interpret API specifications, OpenAPI/Swagger definitions, and data schemas
• Experience working in Agile/Scrum delivery teams with CI/CD pipelines
• Automated API Testing
• Proven hands-on experience testing complex REST APIs including authentication flows (OAuth2, API keys), request/response validation, status code and error body verification, header inspection, and schema validation
• Proficiency with Postman for API exploration, collection-based test authoring, and environment/variable management; experience using Postman CLI (Newman) for automated collection execution in CI pipelines
• Experience testing asynchronous integration patterns: webhooks, message queues, event-driven architectures not just synchronous request/response
• Understanding of SOAP/XML APIs alongside REST the integration landscape includes both
• Experience with contract testing frameworks (e.g. Pact) desirable
• Performance and NFR Testing
• Hands-on JMeter experience: building test plans from scratch, parameterising with test data, configuring thread groups and ramp profiles, interpreting results, and identifying bottlenecks
• Ability to define meaningful NFR acceptance criteria (latency, throughput, error rate thresholds) and translate these into executable test scenarios
• Experience with distributed load generation and results analysis
• Test Automation Engineering
• Comfortable writing test automation code
• Experience building or contributing to a test automation framework, including CI/CD integration (GitHub Actions, Jenkins, Azure DevOps, or equivalent)
• Familiarity with test reporting and observability tooling
• Test Data Management
• Experience designing test data strategies for environments with PII or regulated data constraints
• Practical experience with service virtualisation / API mocking tools (WireMock, Mockoon, or similar) to simulate third-party dependencies
• Ability to write data generation scripts and manage environment-level test data seeding
• AI-Assisted Testing
• Practical experience using AI coding assistants (e.g. GitHub Copilot, Claude, or similar) to accelerate test authoring and automation development
• Experience using AI tools with API contracts and specifications to generate test cases, synthetic data, and coverage analysis
• Ability to critically evaluate AI-generated test output and apply engineering judgement to ensure quality and relevance

Desirable Skills and Experience

• Experience in UK financial services, insurance, or a regulated industry would be a strong advantage
• Experience with Guidewire ClaimCenter or other insurance platforms
• Knowledge of payment integration testing, including real-time payment rails and payee verification schemes
• Experience with observability tooling (Dynatrace, Azure App Service Logging and OpenTelemetry) to validate integration monitoring and alerting as part of NFR testing