Senior QA Automation Engineer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior QA Automation Engineer based in Estonia. This is a senior-level quality engineering role focused on protecting the reliability, correctness, and scalability of critical payment flows. You’ll combine exploratory testing with an automation-first approach across APIs, distributed services, and external financial integrations. The role offers ownership of end-to-end quality, from test strategy and automation through production debugging and release readiness. You’ll work closely with backend engineers and product teams to define acceptance criteria, improve testability, and strengthen quality gates. The environment is modern and cloud-based, with Java, Spring Boot, REST APIs, React, PHP, AWS, and Playwright at its core. You’ll have the opportunity to influence engineering standards while working on a high-impact fintech platform used for global payments and financial operations. This is an ideal opportunity for a technically strong QA professional who enjoys solving complex problems and building scalable, reliable testing practices. Own end-to-end quality for critical payment journeys, including deposits, payouts, reconciliation, and other business-critical transaction scenarios. Design and execute API-first test strategies covering REST, JSON, HTTP, and complex transaction lifecycles. Build, maintain, and improve automated API and selective UI test suites using Playwright, RestAssured, or comparable frameworks. Develop reusable automation components such as API clients, test data builders, and supporting utilities. Test integrations with external providers, including payment processors and Open Banking services, with particular attention to asynchronous callbacks, polling, retries, and failure scenarios. Investigate production incidents, reproduce defects, analyze logs, database records, and API traces, and contribute to root-cause analysis. Collaborate with backend engineers to improve system testability and work with product teams to establish clear acceptance criteria. Contribute to release quality gates, regression testing strategies, smoke tests, and pre-release validation within CI/CD pipelines. Identify risks across distributed payment systems and proactively strengthen testing coverage, reliability, and engineering quality standards. Explore AI-assisted QA and automation techniques where they can improve testing efficiency and effectiveness. Requirements Proven experience in QA engineering, test automation, or a closely related software quality role, with strong ownership of complex systems. Hands-on experience testing REST APIs, including HTTP, JSON, request/response validation, and API-driven workflows. Strong understanding of backend systems, distributed services, and software integration patterns. Practical experience with test automation frameworks such as Playwright, RestAssured, or similar tools. Ability to diagnose technical issues using application logs, databases, API traces, and other debugging tools. Understanding of asynchronous systems and transaction patterns, including callbacks, queues, polling, retries, and failure handling. Previous experience in payments, fintech, or another environment involving highly reliable transactional systems is strongly valued. Experience working with CI/CD pipelines and integrating automated quality checks into software delivery processes. Strong analytical and problem-solving skills, with the ability to identify risks beyond individual feature requirements. SQL and data-validation skills are an advantage. Experience with distributed systems is a plus. Familiarity with prompt engineering or AI-powered tools for QA and test automation is beneficial. Strong communication and collaboration skills, with the ability to work effectively with engineering and product stakeholders. A proactive mindset and willingness to take ownership of quality impr