Event callbacks are notifications emitted by a platform when something happens, such as a publish action, a template update, or a delivery status change. In practice, event callbacks often arrive via webhooks, but the term also includes in-process hooks or SDK callbacks that let you react inside your own application logic.
Where Event Callbacks Fit in a System
Callbacks sit between your application and external services. They are how asynchronous systems communicate state changes. When you expose a public API, callbacks help external developers build reactive integrations without guessing what happened. For embedded editors, callbacks can signal “draft saved,” “publish succeeded,” or “validation failed,” enabling a smoother product UX.
Observability for Callback-Driven Workflows
Callbacks are only useful if you can trust them. Instrument your pipeline with observability so you can trace an event from emission to processing. Log failures, measure latency, and monitor retries. If you treat callbacks as “fire and forget,” you will eventually face silent failures that are hard to debug, especially when customers depend on the events to trigger business logic.
Handling Errors and Retries
If callbacks trigger customer-facing actions, build safeguards so one bad event cannot cascade. For example, require state checks before executing destructive operations, and implement circuit breakers when failure rates spike. These controls protect you during outages and reduce noisy retry storms.
Callbacks can fail for many reasons: network issues, downtime, schema mismatches, or slow receivers. Use error logging to capture context and correlate failures with deployments. Validate payload versions and implement dead-letter queues so you can reprocess events after fixing issues. Most importantly, design the system so a missed callback does not corrupt state permanently.
Event Callbacks and Topol
Topol supports integration-friendly editing workflows where events and template operations can be monitored and controlled, helping teams build reliable callback-driven systems around email content. Learn more at Topol or create an account at Topol signup.