Identity stitching across clients without inventing a second source of truth

If Android merges anonymous sessions at login and iOS starts a fresh profile, your retention curves will invent phantom users.

Agree on a single identity contract: what is stored before login, what replaces it after login, and how cross-device returns are recognized. Put that contract in the schema, not only in a Slack thread.

Then validate with a small set of known test accounts on every client after each major auth change. Parity fails silently when nobody re-runs the stitch check.

We include identity notes in every Cross-Platform Measurement Audit because funnel work without stitching is guesswork.

Talk with Devroutepoint about applying these practices to your stack, or browse services.