Bertoldo worked on enhancing the coollabsio/coolify-docs repository by developing comprehensive documentation for configuring environment variables in preview deployments. He focused on providing clear, step-by-step Markdown instructions that guide users through managing environment-specific settings within the application. By aligning the documentation closely with the actual environment variable configuration process, Bertoldo aimed to streamline onboarding and reduce support requests. His work demonstrated attention to detail in technical writing and a strong understanding of documentation best practices. The contribution was limited in scope, focusing on a single feature over one month, but addressed a practical need for improved developer guidance and user support.