Marcin Filipiak focused on enhancing the marcin-filipiak/test_wspolpracy repository by developing comprehensive documentation and project planning materials for the Weather Checking Program. Using Markdown and leveraging skills in technical writing and project management, Marcin created and updated user manuals that detail features, requirements, and usage for both console and graphical modes. The work included drafting onboarding guides and a project schedule to clarify scope and streamline future development. While no bugs were addressed, the depth of documentation improved maintainability and onboarding efficiency, enabling smoother collaboration and faster feature delivery for both developers and stakeholders involved in the project.