Senior QA Automation Engineer (AQA/SDET)

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 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