Why can't I find a user in a Segment or Journey, even though their events are being recorded in my application?

This issue typically occurs when a user's device (identified by its Hardware ID, or HWID) is not registered in the specific Pushwoosh project where you are trying to segment or target them — even though events for that User ID or HWID are reaching that project.

Here's why it happens and how to fix it:

1. Device registration is the prerequisite: for a user or device to be included in Segments or entered into Journeys within a Pushwoosh project, the device must first be registered in that specific project. This normally happens automatically when the Pushwoosh SDK initializes in your app build.
2. User association: if you identify users with a User ID, associate it with the registered device using the setUserId SDK method in the same project. This is the only method for the job — Android, iOS and React Native all expose setUserId; there is no registerUser method in the current SDKs.
3. Event tracking is not the same as targeting: Pushwoosh can record events linked to a User ID or HWID even when the device is not registered in that project (typically when events arrive via the API or an integration such as Amplitude). But you cannot target that user through Segments or Journeys there unless the device is registered and, where applicable, linked to the User ID.
4. Most common cause — staging/production mismatch:
   • Your test device is registered under your Production Application Code.
   • You then test an event or Journey in your Staging build, which uses the Staging Application Code.
   • The event lands in the Staging project correctly, but because the device is only known in Production, Staging cannot find it to include in Segments or Journeys.

How to resolve:

1. Verify SDK initialization: confirm the SDK in that build is initialized with the correct Application Code for that environment.
2. Confirm device registration: in the Control Panel, open the relevant project and check Audience > User Explorer for the test device's HWID.
3. Confirm the User ID association: ensure setUserId is called after SDK initialization, with the correct User ID, in the correct project.
4. Check integrations: if events come from a third-party system, verify the integration targets the right Application Code and that device registration and User ID association happen via the SDK in that same project.

Note: a single User ID can link up to 20 devices. If a new device is registered beyond that limit, the oldest inactive device is removed automatically — registration itself is not blocked.