Repository backups are a critical component of any robust disaster recovery strategy. However, as repositories grow in size, the process of creating reliable backups becomes increasingly challenging. Our own Rails repository was taking 48 hours to back up — forcing impossible choices between backup frequency and system performance. We wanted to tackle this issue for our customers and for our own users internally. Ultimately, we traced the issue to a 15-year-old Git function with O(N²) complexit...