I think the ArchCom should look over the proposed overhaul of ApiResult (I7b37295e8862b188d). This is a pretty central part of our code base, and we should make sure the proposed changes are in line with what we would like MediaWiki architecture to look like.
Patch: https://gerrit.wikimedia.org/r/#/c/182858/
Original RFC: T482 https://www.mediawiki.org/wiki/Requests_for_comment/API_roadmap