If you already have Segment or another Customer Data Platform (CDP) integrated into your application, you can trigger Knock workflows using existing events without modifying your codebase. A guide is available that explains how to connect these events to workflows, enabling you to utilize the data you are already collecting to enhance your notifications. The guide, primarily focused on Segment, explains how to add Knock as a destination for Segment events, use incoming Segment events as workflow triggers, map Segment data to the required workflow data, and test and debug these event-driven workflows using Knock's tools. Additionally, an example application, Collab.io, is provided to demonstrate features, integrations, and best practices for implementing Knock in applications, with a free tier offered for new users to try out the service.