Webhook Failures: How to Debug and Monitor Reliably

Webhooks are the nervous system of real-time automation. When a new order arrives in Shopify, a webhook fires immediately to your Make.com scenario, triggering the entire fulfillment chain. Unlike polling, which checks for new data on a schedule, webhooks deliver data instantly. But that speed comes with fragility. When a webhook fails, there is no second chance unless you build one. This guide covers the most common webhook failure modes and how to build monitoring that catches problems before your customers do.

Understanding How Webhooks Fail

Webhooks fail silently. Unlike a broken API call that returns an error code to your automation, a failed webhook simply means data never arrives. Your automation does not run at all, so there is nothing in your execution logs to investigate. This is why webhook monitoring requires a fundamentally different approach than API error handling.

"The most dangerous webhook failure is the one you never know about. If your scenario never triggers, there is no error log to check."

Failure Mode 1: Endpoint Timeout

Most webhook senders expect a response within 5 to 30 seconds. If your Make.com or Zapier endpoint does not respond in time, typically because the platform is under load or your scenario is complex, the sender marks the delivery as failed. Shopify, for example, retries webhook deliveries up to 19 times over 48 hours before giving up entirely and potentially deregistering the webhook. If you are unaware of these retries, you may see delayed or duplicated data.

Fix: Your webhook endpoint should return a 200 OK response immediately, before processing the data. Make.com does this natively with its webhook modules. If you are using custom endpoints, ensure the response is sent before any heavy processing begins. For complex workflows, have the webhook write the payload to a queue and let a separate scenario handle the processing asynchronously.

Figure 1: When webhooks go silent, follow this decision tree to identify the root cause and apply the correct fix.

Failure Mode 2: Webhook Deregistration

Many platforms automatically deregister webhook subscriptions if they receive too many consecutive failure responses or if your app's API credentials expire. Shopify removes webhooks after 19 consecutive failures. WooCommerce deactivates them after a configurable number of failed deliveries. Once deregistered, your automation simply stops receiving events with no warning.

Fix: Build a daily health check that queries the source platform's webhook subscription list and verifies your endpoint is still registered. In Make.com, create a simple scheduled scenario that calls the Shopify Webhooks API and checks if your webhook URL exists. If it does not, the scenario automatically re-registers it and sends you an alert.

Failure Mode 3: Payload Schema Changes

When the sending platform updates its API, the webhook payload structure can change. A field that was previously at the top level moves inside a nested object. A date format changes from Unix timestamp to ISO 8601. Your automation, expecting the old structure, either crashes or silently processes incorrect data.

Fix: Version your webhook handling. When you receive a payload, validate its structure against your expected schema before processing. Log any payloads that do not match so you can adapt your automation before issues accumulate. Subscribe to the sending platform's changelog or developer newsletter to get advance notice of breaking changes.

Failure Mode 4: Duplicate Deliveries

Webhook senders retry failed deliveries, and sometimes deliveries succeed but the acknowledgment is lost. This results in your automation receiving the same event twice. Without deduplication logic, you process the same order or update twice. This intersects directly with the duplicate order problem.

Fix: Every webhook payload includes an event ID or a unique reference. Store these IDs and check against them at the start of each execution. If the event has already been processed, skip it. This idempotency check should be the very first step after receiving any webhook.

Building Reliable Webhook Monitoring

Production webhook monitoring has three layers. The first is a heartbeat test: send a synthetic webhook every hour and verify it arrives. If it does not, your endpoint is down. The second is a volume comparison: count the events the source platform reports sending and compare to the events your automation received. Any gap means dropped data. The third is latency tracking: measure the time between event creation in the source and processing completion in your automation.

Figure 2: Combine all three monitoring layers into a single dashboard for comprehensive webhook health visibility.

Webhooks are powerful but demand respect. They are not fire-and-forget; they are fire-and-verify. If your business depends on real-time data flow through webhooks, invest in the monitoring infrastructure to match. For related troubleshooting, see our guides on API rate limiting and Make.com scenario errors, both of which interact closely with webhook reliability in production automation systems.