Senior Backend QA Engineer – API & Database Testing

Ignite quality assurance excellence — elevate backend systems to new standards! Kraków-based opportunity with hybrid work model (up to 3 remote days per week). As a Senior Backend QA Engineer, you will be working for our client, a global leader in delivering innovative backend solutions. You will play a pivotal role in ensuring the robustness, reliability, and security of backend services and APIs built on .NET and SQL, contributing directly to the seamless operation and trustworthiness of their digital platforms. This is an exciting opportunity to impact mission-critical systems and advance your career within a dynamic, international environment. Your main responsibilities: • Design, develop, and execute comprehensive test cases for backend services, APIs, and databases. • Perform integration, regression, and system testing on .NET backend applications. • Validate data integrity and business logic within SQL databases, including stored procedures and complex queries. • Test and validate RESTful APIs using tools such as Postman or Swagger. • Analyze system requirements and craft effective test strategies to ensure full coverage. • Identify, document, and track defects, collaborating closely with developers to facilitate rapid resolution. • Contribute to the continuous improvement of QA processes and best practices. • Support CI/CD pipelines by integrating automated tests and assisting ongoing deployment activities. You're ideal for this role if you have: • At least 5 years of experience as a Software Tester or QA Engineer, preferably focused on backend or API testing. • Strong hands-on experience testing .NET backend code and services. • 2+ years of practical API testing and validation experience. • Proficiency in SQL, including the ability to craft and execute complex queries and test stored procedures. • Solid understanding of CI/CD pipelines and experience with tools like Jenkins or Azure DevOps. • Knowledge of software engineering best practices, including SOLID principles, TDD, and data validation. • Experience analyzing logs and debugging backend issues. It is a strong plus if you have: (optional)• Experience with performance and load testing tools such as JMeter or k6. • Knowledge of microservices architecture and cloud platforms like Azure. • Understanding of security testing for backend services. Language Required for the role: • Fluency in English (good command). Eligibility for the role: • Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.