Senior QA Automation Engineer

Position Summary: We're looking for a strong Senior QA Engineer with leadership experience — someone who can not only design and maintain automated testing for backend and data-heavy systems in the blockchain domain, but also shape the team's technical vision, influence architectural decisions, and own product quality on a long-term basis. This is a fully remote role, and we welcome applications from anywhere in Europe. As part of our Nexus squad, you will play a critical role in streamlining clients’ operations and smoothing their investigations on the Crystal platform. More details: crystalintelligence.com Duties and responsibilities: Design, develop, and maintain automated tests for backend/API and frontend services and data-processing systems in the blockchain domain, including API, integration, contract, and data validation coverage Create reliable test coverage for edge cases such as missing data, delayed data, and incorrect calculations Analyze failed tests and production-like issues using logs, metrics, monitoring dashboards, API responses Conduct code reviews Pioneer new approaches, architectures, or frameworks that drive the business forward Focus on long-term systemic planning, making high-level trade-offs across projects, and establishing technical vision Prioritize testing efforts based on business needs, project risks, and delivery timelines Identify process improvement opportunities and implement QA best practices Evaluate and drive adoption of AI tools for QA and development workflows (e.g., AI-assisted test generation, code review, automation frameworks) Define best practices and guidelines for using AI tools within the QA process, and help the team integrate them effectively Collaborate closely with developers, business stakeholders, and cross-functional teams to improve testability, observability, and reliability of services Maintain test documentation, automation coverage notes, and clear defect reports Required: 5+ years of AQA/SDET experience testing complex backend, API, data-heavy, or distributed systems Deep understanding of SOLID principles and design patterns, hands-on experience applying them into test frameworks; Solid SQL and PostgreSQL experience, including advanced queries, data validation, and investigation of data inconsistencies Strong test design skills Understanding of backend architecture, environment-based configuration, service health checks, and deployment validation Strong Java programming skills for test automation Hands-on experience with test automation tools and frameworks (e.g., Playwright, Postman, REST-assured or similar for API testing; Allure for reporting) Experience of working with version control systems (GIT); Experience working in Scrum or another Agile delivery process Hands-on experience with AI-assisted development tools such as Cursor and Claude, including creating custom skills, agents, and rules to support QA/development workflows Hands-on experience with AI no-code tools and business process automation (e.g., n8n) Proficiency in English Would be a plus: QA technical leadership experienceExperience in performance testingPython knowledge Tech stack: Languages: Java (primary, for test automation); Python (nice to have, such as backend is written on this language)Database: PostgreSQLTest automation: Playwright, Postman or REST-assured (API testing), Allure (reporting)CI/CD: GitHub ActionsAI & Automation Tooling: Cursor or Claude for AI-assisted development, n8n for workflow automation (e.g., Jira ticket automation, bug-report pipelines)Project & Collaboration Tools: Jira, ClickHouse, Mintlify, Drata (compliance tooling), Spira (test case management), Tailscale