Yunchih worked on the PrairieLearn/PrairieLearn repository, focusing on improving container networking for development and production environments. They implemented Docker Compose inter-container networking by adding a host.docker.internal mapping (172.17.0.1) to the extra_hosts configuration, enabling reliable communication between workspace containers. This change, written in YAML and leveraging DevOps and Docker skills, aligned networking behavior across environments, reducing orchestration friction and improving test reliability. Although the work was limited to a single feature over one month, the solution addressed a specific integration challenge and contributed to smoother deployments and accelerated testing cycles, demonstrating a focused and practical engineering approach.