At the time of writing, Lemmyworld has the second highest number of active users (compared to all lemmy instances)
Also at the time of writing, Lemmyworld has >99% uptime.
By comparison, other lemmy instances with as many users as Lemmyworld keep going down.
What optimizations has Lemmyworld made to their hosting configuration that has made it more resilient than other instances’ hosting configurations?
See also Does Lemmy cache the frontpage by default (read-only)? on !lemmy_support@lemmy.ml
I bet you could do it if your instance didn’t pull in a lot of traffic.
If it did… I reckon that you might be able to pull it off to a certain extent so long as your internet package was good enough, but if you got hit with a Reddit-level flood of incoming users, your network almost certainly wouldn’t be able to keep up.
Even if it could, if you were consistently eating through all the upload bandwidth, I reckon you’d draw the eyes of your ISP and they might send you a letter kindly and respectfully telling you that if you don’t upgrade to a commercial line they’re not renewing your contract.