A funnel step is a definition, not a chart
Teams argue about drop-offs when “activated” means different things to growth and engineering. One counts first session; another counts a completed profile; a third counts a paid trial start.
Write the definition first: entry condition, success event, allowed time window, and what does not count. Then instrument. Charts become a verification tool rather than a negotiation surface.
In funnel reconstruction work we leave a one-page definition per step. Product owns the meaning; engineering owns the fire; analytics ops owns the weekly check that both still match.