GitHub’s Engineering Team has moved to Codespaces

This post details the GitHub.com engineering team's migration to GitHub Codespaces for their primary development environment. It outlines the challenges of the previous macOS-centric, brittle local development setup, including long bootstrap times (45 minutes) and fragility. The post describes the technical steps taken to reduce Codespace creation time: implementing shallow clones (reducing clone time from 20 minutes to 90 seconds), using a nightly GitHub Action to build and push a Docker image of dependencies for near-bootstrapped environments, and finally introducing prebuilds to achieve an "instant-on" experience (10 seconds). It also highlights the increased leverage gained, such as upgrading VM specs (from 8-core/16GB RAM to 32-core/64GB RAM) with a single configuration change and streamlining the internal review lab process by providing live preview URLs from Codespaces.