A write takes a different path back to the application

Application

Optional optimistic local state

↓ Write through the API

API → Postgres

Postgres commits or rejects the write

↓ API response returns separately

Postgres → Sync engine

Committed changes, including other clients’ writes

↓ Sync back

Local dataset

Reconcile optimistic state or roll it back

The API response and the local synchronized update are separate events.

The application sends mutations through its API to Postgres. An API response returns on that path. Separately, committed changes flow from Postgres through a read-path sync engine to the local dataset. Optional optimistic local state must be reconciled with the authoritative result. Other clients also write to the same Postgres database. The animation illustrates a successful commit; a rejected write returns through the API and its pending local change is rolled back. Animation timing is illustrative, not a latency measurement. The three steps advance automatically; select a tab to jump to that step.