This Timeline of Events a bit scares me. It looks like, if someone hadn't decided to stop DDOS, deno would still had problems. I would expect to cut off all DDOS traffic on some gateway level, or so.
They addressed the issue by scaling up but the scale up itself ended up lagging behind the database. If that attack happens again presumably the bigger database + caching would mitigate it.
But that would incur a proportionally large cost on the infra I assume? Being able to cutoff DDOS at a gateway level by some sort of filter criteria would still be quite useful imo.