Scaling can take time but they've had at least a year to prepare. It's not like any demand increase they've seen was overnight...

At most normal companies you monitor your systems and address potential bottlenecks before they reach a tipping point. And generally you want enough headroom that a sudden 2-3x increase in demand wouldn't take out the service.

Either Github's technical leadership/talent is completely out of their depth (seems unlikely), or they're not hiring enough engineers to work on these capacity issues.