iOS client
ATT, SKAN postbacks, and a privacy threshold that will swallow your long tail. Client events are late, sampled, or missing on purpose. Treat them as media-readable, not ledger-readable, unless a server callback confirms the same moment.
Signal Atlas
A map of what each surface is allowed to confess.
Cross-Platform App Analytics fails when teams treat every emitter as a peer. The Atlas is our public sketch of the constraints — not a vendor comparison chart.
Use it as a reading order. Inventory first, identity second, windows third, contracts last. Jumping to dashboards is how three purchase totals appear before anyone has named a session.
Android client
GAID availability depends on Play services, OEM skins, and user settings. Background restrictions quietly drop session ends. Instant apps and widgets are emitters people forget until the warehouse looks haunted.
Mobile web & webview
UTMs still work until a webview strips them. Double-fires are common when the same pixel lives in the page and the native wrapper. Consent banners that only hide the UI still send beacons — we treat that as a bug, not a feature.
Server & ledger
Payment callbacks, ticket issuance, and cron jobs are often the only honest success events. They arrive without campaign metadata. The Atlas lesson is to keep them pure, then join campaign keys with documented loss — never invent the join.
MMP & store reports
Useful as a media mirror. Dangerous as a product source of truth. Post-install events may be modelled. Uninstalls are rumours. Export the logs; do not screenshot the UI and call it governance.
Warehouse
The only place a contract can live, because it can hold the exclusions. If a definition cannot be written as a query plus a paragraph, it is not a definition yet. Latency is a feature: late truth beats early fiction.
How cohorts use the Atlas
In Attribution Across Surfaces, week one is a blank Atlas filled with your actual package names, bundle IDs, and web hosts. Students are not allowed to add a dashboard screenshot until every emitter has a row: what it can say, what it cannot say, and who owns the schema.
Steward Circle companies pin a printed Atlas in the analytics bay. When a new surface ships — a mini-app, a smartwatch companion, a partner WebView — the row is added before the first campaign runs against it. That single habit prevents half the reconciliation theatre we see in Bangkok kick-offs.
The Atlas is not a certification. It will not make SKAN and GA4 agree. It will make the disagreement boring enough to manage.
Take the Atlas into a course · Ask for a Steward Circle reading