Worked on the topmonks/hlidac-shopu repository, focusing on backend reliability and integration quality using JavaScript, Node.js, and GraphQL. Addressed silent data issues by implementing robust error handling in the Mall Actor, ensuring that GraphQL failures now throw exceptions rather than being silently logged. Improved user experience for Pilulka Black Friday promotions by correcting country-specific URL and path generation, which resolved navigation inconsistencies across regions. Enhanced package management by externalizing Apify as a peer dependency, reducing version conflicts and simplifying integration for consuming projects. The work demonstrated attention to detail in backend development and a methodical approach to improving system robustness.