Mario Klassen focused on improving the accuracy of developer documentation in the shopware/docs repository during March 2025. He identified and corrected an outdated icon reference in the Add Custom Module Guide, updating the icon name to match the current icon library and prevent setup errors for new developers. Working primarily with Markdown and leveraging his documentation skills, Mario ensured that the guide accurately reflected the available UI icons, which directly improved onboarding and reduced support requests. His targeted fix demonstrated attention to detail and contributed to higher documentation quality, though his work during this period was limited to a single bug fix.