18 May 2026 · Priya Menon
Versioning an event without breaking last quarter
Renaming in place feels tidy on Monday. By Friday the quarter comparison is a collage of two meanings.
An event named signup_completed meant “email verified” in January. In March the product dropped verification and the same name meant “account record created.” The chart went up. The business did not.
We stamp a plan version and we treat a change of meaning as a new event, or as a property that records the definition in force. signup_completed with definition: v2 is honest. Overwriting the old name is not.
Retirement needs a date. The dictionary should say when the old name stops firing, who owns the cut, and which funnel must be rebuilt. Silent dual-firing for a week is sometimes the right cost. Silent dual-firing forever is how you get two truths.
Engineers prefer a single string that never changes. Finance prefers a number that still matches the board pack. The tracking plan is the place those two preferences are written down, before the release notes go out.
If you cannot name the owner of an event, you are not ready to change it. Unowned events accumulate like spare keys. Schema planning starts by writing the owner next to the name, even if the owner is a squad rather than a person.