Aaron Renner shared his positive experience using Earthly for building and testing the Phoenix project, an Elixir-based application. The transition of the project's CI pipeline to Earthly was facilitated by a pull request from Adam Gordon Bell in early October, and while the setup is more intricate than initial examples, it significantly improved Renner's workflow. While Earthly doesn't replace local testing during test-driven development cycles, it helps minimize failed builds on GitHub Actions by running the build locally beforehand. Renner believes Earthly represents the next generation of CI tools that bridge the gap between local and CI builds and encourages others to explore its potential.