I am a senior frontend developer with React.js, with over 9 years of experience in creating, optimizing user interfaces and frontend components for web and mobile applications. I have worked in various industries, such as real estate, transportation and insurance, delivering high-quality and user-friendly solutions for different clients and users. I have the following skills and qualifications:- Expertise in building frontend single page applications with React.js and Redux, using modern web technologies such as HTML5, CSS3, SASS and JavaScript,- Experience in applying object-oriented programming principles, agile methodologies, code review practices and mentoring junior developers,- Proficiency in using Github, Git, Scrum, and JIRA for version control, collaboration and project management,- Upper Intermediate knowledge of English and being part of a German-Polish team,- Knowledge of performance testing frameworks such as Jest, as well as browser-based debugging and performance testing tools,- Ability to design and implement frontend architecture to support user interface concepts, troubleshoot and debug application codes, monitor and improve frontend performance and document application changes and updates.