The bridge to agent-scale Git infrastructure

GitHub has migrated 99.99999% of its Git repositories to run across both its data centers and Azure cloud infrastructure to handle exponential traffic growth, with the remaining busiest repositories delayed by a 25-millisecond latency issue. To resolve this constraint, GitHub modified its write serialization process to apply consistency requirements per individual reference rather than repository-wide, allowing independent reference updates to proceed in parallel without waiting for all replicas to respond. This architectural change enables even the busiest repositories to move to Azure while paving the way for future scalability improvements.