Marek Sokol updated the documentation for the apollographql/apollo-client repository, focusing on correcting API reference links for ErrorLink and RetryLink. By revising Markdown files and applying technical writing skills, Marek ensured that the documentation now points to accurate, navigable API resources. This change addressed confusion around error handling and improved the onboarding experience for developers integrating Apollo Client. The update was tracked through a single, traceable commit, reflecting a targeted approach to documentation maintenance. While the work was limited in scope and duration, it demonstrated attention to detail and a clear understanding of how precise documentation supports developer productivity and troubleshooting.