The #100DaysOfGatsby 2021 challenge reached its conclusion on April 12th, marking the 100th day of the year and the end of this year's event. Participants, assuming the role of "Dev" at a fictional startup, progressed through a series of five challenges designed to build and enhance a Gatsby site. These tasks included creating a proof of concept using Contentful, launching a site with improved style and performance, integrating a WordPress blog, adding a Shopify swag store, and developing a Gatsby Theme for site scalability. Each challenge aimed to demonstrate Gatsby's capabilities in handling multiple data sources and customizing sites through its plugin ecosystem. Participants received support through Gatsby's GitHub Discussions forum, Discord community, and instructional videos. The challenge fostered a community of developers who shared progress and solutions, and it encouraged ongoing participation with the promise of another round starting January 1, 2022.