Every app that survives its second year carries a tracking plan written in a hurry. The verbs were optimistic. The nouns were copied from a blog post. Someone added cta_clicked because a designer wanted to know which button “won,” and three quarters later the warehouse still receives that event from a screen that no longer exists.
In Event Taxonomy Studio we treat a schema as a public language. Once a property is in production, it has readers: a Looker explore, a board PNG, a data-science notebook, a contractor who left in 2023. Renaming plan_type to subscription_tier is not a refactor. It is a negotiation with every reader who will not attend your meeting.
The cheaper move is versioning in place. Add the clearer name, keep the old one emitting for a documented sunset, and write the sunset in the measurement diary so it cannot be “remembered” as optional. Teams that skip the sunset discover, a year later, that finance still joins on the ghost column.
We ask students to kill five events before they propose five new ones. The kill list is the actual work. New events are easy to invent in a workshop; retiring them requires someone to tell a stakeholder that a chart will go dark. If nobody in the room has that authority, the taxonomy will only grow, and App Analytics becomes a compost heap with a pretty lid.
A schema you cannot unship is not a tragedy. It is a reminder that instrumentation is closer to publishing than to interior decorating. Print the current plan. Date it. Argue with it. Then change as little as the product truly requires.