Senior QA Automation Engineer - Remote, Blockchain Testing

Crystal Intelligence; Warszawa; On-site; PLN 336,699 - 486,344; Full time

Job summary

Crystal Intelligence is seeking a Senior QA Engineer with leadership experience to design and maintain automated testing for backend and data-heavy systems in the blockchain domain, and to shape the team's technical vision and long-term product quality.

This is a fully remote role across Europe. You will design tests for API, backend, and frontend, review code, drive QA best practices, and explore AI-assisted tooling to improve observability and reliability.

Qualifications

• Minimum 5+ years of experience in QA automation and testing of complex backend/API/data-heavy systems.
• Strong understanding of SOLID principles and design patterns applied to test frameworks.
• Proficient SQL and PostgreSQL experience with data validation and anomaly investigation.

Responsibilities

• Design, develop, and maintain automated tests for backend/API and frontend services and data-processing systems.
• 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, and API responses.
• Conduct code reviews and promote QA best practices.
• Pioneer new approaches or frameworks to improve testing and reliability.
• Define QA processes and guide AI-assisted testing adoption within the team.
• Collaborate with developers and stakeholders to improve testability, observability, and reliability.

Skills

SDET

Test Automation

Java

SQL

PostgreSQL

CI/CD

Agile

English

AI tools

Code reviews

Tools

Playwright

Postman

REST-assured

Allure

Git

Jira

n8n

Cursor

Claude

Job description

Crystal Intelligence is seeking a Senior QA Engineer with leadership experience to design and maintain automated testing for backend and data-heavy systems in the blockchain domain, and to shape the team's technical vision and long-term product quality.

This is a fully remote role across Europe. You will design tests for API, backend, and frontend, review code, drive QA best practices, and explore AI-assisted tooling to improve observability and reliability.