About the role
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.
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 experience
* Experience in performance testing
* Python knowledge
Tech stack:
* Languages: Java (primary, for test automation); Python (nice to have, such as backend is written on this language)
* Database: PostgreSQL
* Test automation: Playwright, Postman or REST-assured (API testing), Allure (reporting)
* CI/CD: GitHub Actions
* AI & 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