QA-Test Engineer

QA Test Engineer (API Integration & Performance Testing)

We are looking for an experienced QA Test Engineer to join an international telecommunications project focused on API integration and migration.

You will be responsible for validating API implementations, ensuring functional parity between MuleSoft and Quickwork, conducting performance and regression testing, and supporting UAT and production cutover decisions.

You will collaborate closely with Integration Developers, the Technical Lead, and the MuleSoft SME.

Responsibilities

• Design and execute API integration, end-to-end, regression, and UAT tests.

• Build and maintain Postman collections and automate test execution using Newman.

• Generate Newman HTML reports and prepare test evidence for UAT sign-off.

• Perform API parity testing between MuleSoft and Quickwork implementations, comparing HTTP status codes, response schemas, and payloads.

• Investigate discrepancies and distinguish expected behavioral differences from actual defects.

• Develop multi-step API test scenarios with authentication token and state management.

• Plan and execute performance tests using JMeter, k6, Gatling, or similar tools.

• Conduct baseline, load, sustained-load, and peak-load testing, analyzing latency, throughput, p95/p99 response times, and bottlenecks.

• Verify the TARDIS 60-second timeout requirement under production-like conditions.

• Design regression coverage to ensure existing APIs remain unaffected by the migration and cutover.

• Prepare and manage synthetic test data for B2B APIs.

• Integrate automated API tests into GitLab CI/CD pipelines, ensuring test failures block the relevant pipeline stage.

• Lead UAT execution and prepare structured reports with clear pass/fail evidence for Technical Lead review and Project Manager sign-off.

Requirements

• 5+ years of experience in API integration testing and test automation.

• Strong practical knowledge of API testing tools and automation frameworks.

• Experience with API migration, re-platforming, or parallel deployment projects, particularly API parity testing.

• Hands-on experience with Postman and Newman, including environments, variables, authentication tokens, and HTML reporting.

• Experience with RestAssured, pytest-requests, or similar API testing frameworks.

• Understanding of contract testing approaches, such as Pact.

• Practical experience with performance testing tools such as JMeter, k6, or Gatling.

• Ability to create realistic load scenarios involving concurrent users, request distribution, and think time.

• Understanding of application latency, network latency, and test-harness overhead.

• Strong knowledge of test design techniques, including equivalence partitioning, boundary value analysis, and regression testing.

• Experience working with OpenAPI 3.0 specifications.

• Experience with synthetic test data and B2B wholesale API schemas, including TM Forum (TMF) and MEF.

• Experience integrating automated tests into GitLab CI/CD pipelines.

• Solid understanding of UAT processes, test reporting, and formal sign-off.

Nice to Have

• Experience testing MuleSoft integrations.

• Familiarity with Quickwork or similar integration platforms.

• Experience supporting production cutovers and API migration validation.

Project Details

• Industry: Telecommunications

• Location: Remote

• Engagement: Contract project

If you have strong API testing expertise and experience validating complex integrations and migrations, we would be happy to hear from you!