Comment by Anon1096

Cloudflare and other cloud infra providers are only providing primitives to use, in this case WAF. They have target uptimes and it's never 100%. It's up to the people actually making end user services (like your medical devices) to judge whether that is enough and if not to design your service around it.

(and also, rolling your own version of WAF is probably not the right answer if you need better uptime. It's exceedingly unlikely a medical devices company will beat CF at this game.)