Based on the provided knowledge sources, I don't have enough information to definitively answer whether Airbyte supports multiple webhooks for the same event (successful sync) to notify both a microservice and send a Slack notification simultaneously. However, the current information suggests that Airbyte's notification system is primarily designed for Slack notifications, with limited support for other webhook-based notifications: 1. The documentation shows how to set up Slack notifications for successful syncs [Configure Webhook Notification Settings](
https://docs.airbyte.com/cloud/managing-airbyte-cloud/manage-airbyte-cloud-notifications#enable-the-slack-notification-in-airbyte). 2. There's an open GitHub issue requesting support for notification preferences per connection, which indicates that the current system might be limited [Github Issue: Notification Preferences per Connection](
https://github.com/airbytehq/airbyte/issues/8037). 3. A comment on another GitHub issue states that JSON payloads are only offered for Failed & Successful syncs, but not for other notification types [Github Issue: Airbyte Integration Missing Payload for Zulip Notifications](
https://github.com/airbytehq/airbyte/issues/46557). Given this information, it appears that Airbyte's current notification system is not designed to support multiple webhooks for the same event. If you need this functionality, you might want to consider submitting a feature request to the Airbyte team or exploring custom solutions using their API if available.