example from 2021:
https://variety.com/2021/digital/news/twitter-down-outage-12...
2021 was well beyond the growing pains in the "failwhale" period.
I don't recall seeing it on HN though.
It's been in and out today.
[1] https://cdn.mos.cms.futurecdn.net/Ky6zydYw5QPEfVKV4UT7j9-970...
Depending on the nature of the DDoS, you may block it at other parts of the stack.
(Referring to when Elon used bolt cutters in the datacenter)