Hiller contributed to the justjavac/deno-docs repository by enhancing the quality and accuracy of API documentation for the Deno Docs project. Focusing on the Request constructor, Hiller updated parameter naming and revised code examples to use 'resource' instead of 'input', ensuring alignment with the actual API and reducing potential confusion for developers. The work involved authoring and version-controlling Markdown documentation, applying precise naming conventions, and collaborating through issue tracking to address project needs. While the scope was limited to documentation improvements over one month, these changes improved onboarding efficiency and clarity for API consumers, demonstrating attention to detail and effective communication.