A minimum of five years of professional experience in software development., Strong hands-on expertise with React and Java., Commercial experience with unit testing on both frontend and backend platforms., Proven ability to write performant, maintainable, and testable code., Excellent command of the Polish language (C1 level or higher)., Excellent command of the English language (C1 level or higher)., Effective communication skills and a collaborative approach to teamwork., Willingness to mentor and support the development of others., Comprehensive architectural understanding of web applications, including considerations of performance, quality, and security.