We are **tech transformation** specialists, uniting human expertise with AI to create scalable tech solutions. With over 7,400 CI\&Ters around the world, we’ve built partnerships with more than 1,000 clients during our 30 years of history. Artificial Intelligence is our reality. We seek an Senior SDET to grow API test coverage and performance scenarios focused on application security. This role partners with the API \& Performance Frameworks lead to author and maintain high\-value tests across critical services, ensuring resilience and reliability at scale. It also includes supporting developers with unit and integration testing. We value self\-starting, self\-driven and proactive engineers who thrive in a fast\-paced, startup\-like environment and can adapt to frequent changes in direction.**Responsibilities** Author and maintain API test cases using existing contract and integration frameworks, expanding coverage across high\-traffic endpoints. Develop and execute negative, edge, and performance scenarios to ensure robustness against unexpected inputs and loads. Maintain and evolve test data fixtures for APIs to support integration and regression runs. Collaborate with the framework lead to integrate authored tests into CodeBuild/GitHub CI pipelines, contributing to reliable release gates. Use tools such as k6 (or equivalent) to author and extend load/performance test profiles. Ensure service\-level gates are enforced (e.g., p95/p99 latency, throughput, error rate) by incorporating performance checks into test suites. **Qualifications** Proven experience in API testing (REST/GraphQL/gRPC), including automation and contract/integration test development. Familiarity with consumer\-driven contract testing and service\-level validation. Experience with performance/load testing tools (e.g., k6, JMeter, Locust) and interpreting performance metrics. Strong background in JavaScript/TypeScript or Python for test automation. Hands\-on experience with CI/CD systems (e.g., GitHub Actions, AWS CodeBuild) and integrating test suites. Detail\-oriented with a passion for building scalable, maintainable test suites that improve software quality. **Our benefits include:*** Premium Healthcare * Meal voucher * Maternity and Parental leaves * Mobile services subsidy * Sick pay\-Life insurance * CI\&T University * Colombian Holidays * Paid Vacations And many others. Collaboration is our superpower, diversity unites us, and excellence is our standard. We value diverse identities and life experiences, fostering a diverse, inclusive, and safe work environment. We encourage applications from diverse and underrepresented groups to our job positions.