[OUTBOUND WEBHOOKS] Outbound Webhooks API errors in Prod2 and Prod4

Update timeline

1. identified Dec 10, 2025, 03:38 AM UTC

   Kustomer is aware of an event affecting outbound webhook delivery in our Prod2 environment. Customers may experience failures due to 404 and 503 errors when the platform attempts to send outbound webhooks. Our team is actively investigating the cause and working toward a resolution. Please expect additional updates within the next 30 minutes, and reach out to Kustomer Support at [email protected] if you have additional questions or concerns.

2. identified Dec 10, 2025, 03:55 AM UTC

   We are continuing to work on a fix for this issue.

3. monitoring Dec 10, 2025, 04:22 AM UTC

   Kustomer has implemented a fix for the event impacting outbound webhooks in the Prod2 and Prod4 environments. We are backporting this fix across environments, and our team is monitoring to ensure service stability and continued recovery. Please expect additional updates within the next 30 minutes, and reach out to Kustomer support at [email protected] if you have additional questions or concerns.

4. resolved Dec 10, 2025, 04:52 AM UTC

   Kustomer has resolved the event that impacted outbound webhooks in the Prod2 and Prod4 environments. The backported fix has been fully deployed, and webhook delivery is functioning as expected across all affected environments. Our team has verified stability, and no further impact is anticipated. If you have additional questions or concerns, please reach out to Kustomer support at [email protected]

5. postmortem Feb 12, 2026, 04:57 PM UTC

   ### **Summary** On December 9, 2025, Kustomer experienced an interruption to outbound webhook delivery affecting customers in our **prod-2 \(EU\)** and **prod-4 \(IN\)** production regions. During this time, some outbound webhook requests were unable to reach customer endpoints, resulting in delivery failures and error responses. The disruption occurred during a routine platform update related to our deployment systems. An underlying inconsistency from a previous infrastructure change caused a required backend service to become temporarily unavailable while updates were in progress. As a result, webhook endpoints could not accept or process delivery attempts for a limited period. Engineering teams identified the issue quickly and restored full service shortly thereafter. Once the affected systems were brought back online, normal webhook delivery resumed and any queued events were successfully processed. There was no permanent data loss, and webhook functionality returned to normal operation across all impacted regions. ### **Impact** * **Duration:** Approximately 1 hour and 40 minutes * **Scope:** Production regions prod-2 and prod-4 * **Customer Impact:** * Outbound webhook delivery failures during the incident window * Webhook requests may have returned HTTP 503 or 404 responses * Webhook events were delayed but not lost ### **Next Steps** While safeguards already exist to protect core platform services, we are implementing additional improvements to reduce the likelihood of similar disruptions in the future. These include strengthening validation during platform updates, improving detection of incomplete infrastructure changes, and enhancing internal visibility when critical services are modified.