st2 reminds me a lot of what we're building at https://github.com/keephq/keep (i maintain this oss), there are a few concepts that i really love but the video in the repo really gives me a 90s feelin'

i can't really seem to understand, there's an "enterprise" (with ldap, etc.) version but couldn't find any pricing info

edit: well it's not focused on alerting but alerting is somewhat kinda "event driven"