One pipeline, many channels
A notification system delivers messages to users across channels, mobile push, sms, email, and in app alerts. The goal is one pipeline that accepts a notification request and reliably routes it to the right channel and provider.
The flow
- A service requests a notification with a recipient, a channel, and content.
- The request lands in a queue so spikes do not overwhelm downstream providers.
- Workers pull from the queue, build the message, and call the channel provider.
- A provider, like a push gateway or an email service, delivers to the device or inbox.
Reliability
- Failed sends are retried with backoff, since providers can be flaky.
- Idempotency keys prevent sending the same notification twice on retry.
- Delivery status is tracked so the system knows what reached the user.
User controls
- Preferences let users opt out of channels or categories.
- Rate limits and batching prevent notification spam.
- A template system keeps content consistent and localizable.
Key idea
A notification system queues requests then routes them through workers to push, sms, or email providers, with retries, idempotency, user preferences, and templates for reliable multi channel delivery.