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
Likely experience and knowledge improving the quality of deployment. Most instances are likely underspecced, are on hosts that aren’t easy to scale up with, or are maxed out in their current offering tier (lemmy.ml comes to mind there)