What you'll be responsible for Test backend services within a REST-based microservice architecture supporting card and payment operations Validate transaction flows, including authorizations, captures, reversals, and refunds Verify back-office processes related to reconciliation, corrections, and operational workflows Perform manual and exploratory testing for new product features and system changes Execute regression testing during releases, infrastructure changes, and platform migrations Create and maintain test cases, checklists, and test documentation Analyze defects, document findings, and work with developers, analysts, and product managers to resolve issues Collect and analyze QA metrics to improve product quality and testing effectiveness Contribute to the automation of transaction flow testing at the API level as test coverage expands What we need Experience testing backend systems and REST APIs Confident use of Postman or similar API testing tools Experience working with PostgreSQL, including writing queries and validating stored data Experience working with Kafka, including event validation, topic analysis, and contract verification Understanding of card processing and payment flows, including authorization, hold, capture, reversal, and chargeback processes Ability to read and understand code written in Java, Kotlin, JavaScript, or similar languages Strong understanding of software testing principles, defect investigation, and test design techniques Good to have Experience testing financial products, payment platforms, or card-processing systems Experience with automated or load testing Familiarity with GitLab CI, CI/CD pipelines, Allure, or similar reporting tools