The Sentry Integration Platform allows developers to build custom integrations that connect Sentry with their software. Internal Integrations provide a simpler authentication model than third-party integrations and are great for creating quick prototypes or testing unique workflow ideas within an organization. An example of an internal integration is the Round Robin Issue Assignment application, which cycles through team members on a given Sentry project, assigning each new issue to a different user until everyone has been assigned. This application demonstrates how easy it is to create custom integrations using Sentry's Internal Integrations. The process involves creating a new internal integration, configuring object permissions, enabling webhooks, and handling the issue-created webhook. Additionally, the integration uses Sentry's Web API to fetch users with access to a given project and update an issue's properties to assign a user.