Wikimedia Product/Analytics Infrastructure/Workflow

References:
 * What is an Event Schema and why do we need them?
 * What is an Event Stream and why do we need them?
 * Why can't I just send raw JSON?
 * Why not develop directly on Beta?
 * Can I skip the Beta step?
 * Help, my application can't use the Beta cluster

Defs:
 * Beta development environment: Applications that are not MediaWiki can have their own development environments or versions, and in these environments or versions, their application code will call APIs etc. belonging to the MediaWiki beta deployment, rather than the production deployment. When developing MediaWiki, it is right to say simply that you "deploy to the beta cluster", but individual applications outside of MediaWiki but which talk to MediaWiki, are more appropriately set up in their own way to talk to the beta cluster. TODO: Figure out better name and use this definition throughout.