Cursor Uses S3 WAL to Scale Git Storage Past 300 Pushes per Second

Cursor introduced Continuity, a Git storage architecture that uses an S3-backed write-ahead log as the source of truth instead of replica coordination. In synthetic tests on its everysphere monorepo it reached up to 120 pushes per second on S3 Standard and over 300 on S3 Express One Zone.

• S3 WAL is the source of truth; local NVMe repos act as warm caches
• Linear read scaling with up to 100 replicas in synthetic tests
• Over 300 pushes per second on S3 Express One Zone, 120 on S3 Standard
• At the higher rate Git compaction became the bottleneck