What EventStream does
EventStream is the server-side collection and routing tier of the Customer Data Hub. Instead of every vendor's tag collecting its own copy in the browser, the site (or app, or backend) sends events once to a first-party collection endpoint; EventStream validates them against your specification and fans them out to destinations through server-side connectors. The browser does less, the data leaves once, and every downstream system receives the same version of the truth.
Why estates move server-side
- Durability - browser tracking restrictions and short-lived cookies degrade client-side collection unevenly per vendor, which is where cross-platform reporting discrepancies are born.
- Consistency - one collection point means one event schema, not per-tag reinterpretations.
- Control - what each destination receives is an explicit server-side mapping, reviewable and minimizable.
- Performance - fewer third-party scripts in the page.
The architecture
| Layer | Role |
|---|---|
| Sources | Web (via the data layer), mobile SDKs, and backend systems sending HTTP events |
| Event specifications | The schema contract: required attributes, types, allowed values - enforced at ingestion |
| EventStream | Validation, transformation, and routing |
| Connectors | Server-side delivery to analytics, advertising, warehouse, CRM destinations |
| Downstream | AudienceStream profiles, warehouse tables, ad platform conversions - all fed from the same stream |
Migration path from client-side
The move is incremental, not big-bang: keep the existing client-side tags running, stand up the collection endpoint and event spec, route one destination server-side, reconcile its numbers against the client-side equivalent, then cut destinations over one at a time as each delta is explained. The reconciliation step is where most projects earn their keep - it is the first time many teams see exactly how much each browser-side integration was losing.
Consent still applies server-side. Moving collection to your infrastructure does not move it outside privacy obligations - consent state must travel with the event and gate connectors. Architecture that treats server-side as a consent bypass is building tomorrow's incident.