User blog comment:MisterWoodhouse/Updates to Discussions and the plan for Forums/@comment-36153576-20200806193454/@comment-20644-20200808185853

CrazypuppyT, what JustLeafy said wasn’t misinformation. Discussions was not built on MediaWiki. It lives alongside MediaWiki on the legacy platform and the UCP, but it was built on its own service without integrating it into MediaWiki. That was done precisely to avoid the problems created by features like Forum: by bolting that sort of feature onto MediaWiki, it becomes more and more difficult to upgrade MediaWiki which is why it’s been so many years since the last update and why it was necessary to make some of the decisions to retire certain features for the UCP.

The fact that Discussions was built on its own service, instead of MediaWiki, is why (unlike Message Wall, Article Comments, and Blogs) it doesn't need to be rebuilt for the UCP.

This blog from 2016 is helpful context for what I mean when I say “service” in terms of software development: "A service, in technological terms, is a small piece of software responsible for doing a single, common task. It can be coded in any language. Service-Oriented Architecture, therefore, is when you design a system that allows all of a website's tasks to be handled by individual services that work together, rather than one giant piece of software that does everything."

MediaWiki is one service on Fandom, and it powers wiki editing. Feeds (the tech behind Discussions and the new Message Wall and Article Comments) is another, and it powers conversation. They can co-exist alongside each other.