Notes
Writing from the practice
Short pieces on measurement choices we see during engagements — not vendor comparisons.
Ship events that answer a question, not a wishlist
If nobody can name the decision an event supports, it probably should not ship.
Retention curves without vanity cohorts
Day-7 return rate is useless if “active” means opened the app for two seconds.
Schema versions that survive three releases
Breaking property renames are cheap on day one and expensive on day ninety.
When experiments lie about exposure
If exposure fires on page load instead of render of the changed UI, your lift is fiction.