Senior QA Engineer — Data Platform - Contractor role

Working hours: 7 AM - 4 PM - Brazilian timezone Days of work: Monday - Friday Employment type: Contractor - indefinite About the Role: We are seeking a Senior QA Engineer to own quality for our Data Platform and Analytics & Reporting products. This role is focused on ensuring the correctness of the pipelines, warehouse models, and reports that power our analytics products. Unlike traditional QA positions, this role is data-first. Most of what we build has little or no user interface. A report is either correct or it isn't—a passing UI test does not guarantee that the numbers behind it are accurate. Success in this role requires someone who enjoys investigating data, writing SQL, validating metrics against raw source data, and working closely with engineering to identify and prevent defects before they reach customers. Experience with API testing and automation frameworks such as Playwright is valuable, but the primary focus is data quality and backend validation. Key Responsibilities: 1) Data Correctness - Validate reports, dashboards, and aggregated metrics before they reach customers. - Reconcile reporting data against upstream APIs and raw source data. - Independently verify calculations rather than relying on downstream reports. - Clarify and document business metric definitions when they are ambiguous. 2) Data Quality Automation - Design and implement automated data quality checks using Soda or similar expectation frameworks. - Validate data freshness, volume, distribution, and business expectations. - Contribute quality checks into data contracts and production monitoring. 3) Pipeline & Platform Testing - Test Airflow DAGs and Databricks jobs. - Validate scheduling, dependencies, backfills, failure recovery, and data integrity throughout the pipeline. 4) API Testing - Develop automated and manual tests for REST and GraphQL APIs. - Validate business logic, data integrity, and service reliability. 5) Test Automation - Build and maintain automated quality checks with a focus on data validation while supporting API and UI automation where appropriate. 6) Communication & Collaboration - Document investigations, defects, and testing results clearly. - Partner closely with Engineering, Product, and Analytics teams. - Present quality risks and findings to both technical and non-technical audiences. Required Qualifications: - 5+ years of QA experience. - Strong SQL skills with the ability to independently write complex queries. - Experience validating data against an upstream source of truth. - Comfortable working with raw API payloads. - Experience investigating reporting or data discrepancies. - 2+ years of automation experience. - Experience testing REST APIs. - Strong analytical and investigative mindset. - Excellent communication skills. - Experience with Playwright (or Selenium/Cypress with a willingness to transition).