It's a bit late to start discussing this task, but late is still better than never.
Let's imagine Lila and the Wikimedia donors saying within a month: alright, we have invested a lot of resources on this Summit. Has it been successful? What have we achieved? Was it worth the investment of money and time? What went well, and what needs to improve?
What data should we be producing and collecting? Some ideas to be discussed, organized by owner:
- Goals of the event satisfied (they'd need to be written down here).
- T88515: MediaWiki Developer Summit 2015 survey
- Media uploaded to Commons.
- Mentions in Wikimedia channels and social media. #MWDS15 hashtag?
- Number of participants / non-WMF / sponsored / not sponsored.
- Origins of participants / non-WMF / sponsored / not sponsored / local.
- Achievements documented in sessions' tasks.
- Remote participation via IRC, mailing lists, hangouts...
- mediawiki.org pages updated. Approximately; needs manual filtering.
- Phabricator tasks created / active / resolved during the event, associated with MediaWiki-Developer-Summit-2015