Wikimedia Platform Engineering/Site performance and architecture

Rationale
Many small architectural changes and improvements are being done all of the time without a lot of fanfare. This is a general activity area where we communicate changes made along these lines.

Documents

 * User requirements:
 * Specifications:
 * Software design document:
 * Test plan:
 * Documentation plan:
 * User interface design docs:
 * Schedule:
 * Task management:
 * Release management plan:
 * Communications plan: