We, Analytics, own the implementation of the Pageview Definition and the application of it in our data pipeline.  We even own the discussions about the definition and we are happy to mediate between different teams (as is happening right now on this list).  What we can't possibly own is the process that keeps the pageview definition up to date with the technical reality.  Because to do that effectively we'd have to code review every line of code that changes how clients request data from our servers, and I think our team isn't big enough to do that even if we did it full time.

So, we rely on our sister teams across WMF to surface changes to our request patterns and anomalies in how those get interpreted by the Pageview definition.  We then rely on the owners of the code to make decisions in collaboration with the Research team about the pageview definition.  We're then happy to implement those changes, test them and help the teams understand whether or not they've accomplished what they set out to do.

An example, to be totally crystal clear.  So the Android app team changed the way it was calling the API to get different pieces of a page.  They reached out to us (awesome, thank you) and we brainstormed.  We gave the Research team a heads up and a chance to comment, but there was no significant departure from how we handled link previews in the past, so we used that knowledge to move forward.  We then implemented a new "preview" flag that's passed via X-Analytics, used it in our UDFs, and deployed everything.  We think this is the perfect teamwork on issues like this, from an ownership perspective.