GitHub scale — 630 million repositories, 180+ million developers

GitHub's Octoverse Report 2025 documents 630 million repositories and over 180 million developers on the platform. GitHub is the largest single deployment of Git and the most widely used software-development platform on the Internet.

For C-0016 (architectural tier is determined by the deployment, not by the underlying software): GitHub is the canonical example of how the same protocol — Git — can deliver Tier 1 resilience when used as a single-platform centralization (commit pushed, never cloned) or Tier 3 resilience when used in its distributed mode (independent clones across developers and mirrors). The 630-million-repository scale is what makes the GitHub-Iran sanctions episode (E-0009) consequential: a single platform's policy decision affected the operational continuity of millions of repositories worldwide.

For C-0011 (Tier 1 is one organizational decision away from the same outcome as Tier 0): GitHub's scale is exactly what makes it a Tier 1 risk concentrator at planetary level. A platform serving 180M developers under a single jurisdiction's export-control regime is a single failure domain enclosing a population that exceeds the population of every research institution combined.