Journal
How event taxonomy debt shows up in weekly KPI reviews
Taxonomy debt rarely announces itself as a data-quality incident. It arrives dressed as a confident funnel. A PM points at a step that grew 12% week on week. Engineering frowns because they did not ship anything that should have moved that step. Both are right. The event fired twice under two names, and the warehouse joined them like strangers at a wedding.
The pattern is almost always the same. Someone added screen_view_checkout because checkout_viewed felt owned by another squad. Someone else added a property source that means campaign in one stream and referrer in another. Nobody wrote a retirement rule. The Monday slide inherited all of it. When we open these dictionaries in Event Taxonomies for Lean Teams, the first hour is not strategy. It is copy-editing.
Debt shows up in weekly reviews in three telltale ways. First, a funnel step that cannot be reproduced from the event contract alone — you need tribal knowledge. Second, a metric whose numerator and denominator silently changed ownership after a re-org, so the trend line is a splice of two definitions. Third, a “new user” count that inflates whenever a background ping is recoded as a session start.
None of these are vendor problems. Vendors will happily ingest duplicate names. The contract is the product: name, owner, join key, retirement rule, PII stance. If a KPI-feeding event lacks any of those five, it does not belong on an exec slide. It can live in a research notebook. It cannot live in a room that allocates headcount.
Teams ask whether they should pause feature work to clean the dictionary. Sometimes yes. A two-week freeze on new events, with a public retirement list, is cheaper than another quarter of arguing about a 12% that never happened. If you cannot freeze, at least stop adding. “Just add a property” is how lean teams recreate the taxonomy they fled.
We do not romanticise governance committees. A single named owner per event, visible in the same doc the warehouse uses, beats a monthly council that rubber-stamps screenshots. If the owner leaves, the event is orphaned until a new owner is written down. Orphan events are ineligible for the Monday slide. That rule sounds harsh until you have watched a funnel double-count a checkout for eleven weeks.
If this note feels like it was written about your board, it probably was written about a board like yours. Bring the dictionary to a lab, or start with Field Ledger worksheets if you are not ready for critique. Either way, stop letting unnamed events speak in the room.