From: Sam, Growth Lead at Lumen Coffee
Subject: Funnel for the first two weeks of June
I need a reproducible, session-level funnel with a device breakdown. Please build it from the BigQuery export: lumen-coffee.analytics_301245.events_*, 1 to 14 June. Count sessions (user_pseudo_id plus the ga_session_id parameter), not events. The steps are session_start, view_item, add_to_cart, begin_checkout and purchase. I'd like the funnel overall, the conversion rate, and the same by device category.
One query, built up step by step. Each step starts from what you wrote in the step before. If you didn't solve the previous step in this session, you get its model answer as the starting point.
The standard GA4 approach is two passes: first one row per session with a flag for each step it reached, then counts over those sessions. Building that session table is the heart of the project.
Repeated events should change the event count without multiplying the session count. Build the session flags before aggregating devices, and use a safe denominator for rates. The last step turns the funnel into a checked recovery-priority report.