Service Incident - 21st of October 2026 - Degraded performance caused by an outage at Schoolyear

All times in the document are recorded in UTC+2 (CEST).
 

Incident summary

On October 21st, 2026, the platform experienced degraded performance from 12:18 to 12:37. Students taking a digital test secured with Schoolyear could not continue their test during this period.

This issue was caused by an outage at Schoolyear, the secure exam environment that integrates with Ans. Ans checks every page a student opens in a Schoolyear-secured digital test with Schoolyear. During the outage, each check took several seconds before failing. These slow checks occupied the capacity of the platform, which made Ans slow for all users.

The platform recovered as soon as Schoolyear resolved their outage. We are developing an improvement that limits how long Ans waits for Schoolyear and temporarily stops contacting Schoolyear after repeated failures. This will help keep Ans responsive for other users during a Schoolyear outage. We will update this post-mortem once the improvement has been deployed.

Lead-up

On October 21st, 2026, at 12:18, Schoolyear started responding slowly and with errors to requests from Ans. Schoolyear has described this as a temporary degraded production availability on their status page.

Fault

When a student opens a page in a digital test secured with Schoolyear, Ans asks Schoolyear to confirm that the student is using the Schoolyear secure environment. Ans waits for this confirmation before it displays the page.

During the outage, Schoolyear took around 6 seconds to answer each request and then returned an error. While Ans waited for these answers, the server capacity that handles requests remained occupied. With hundreds of students opening pages at the same time, little capacity remained for other users, which caused the platform to slow down for everyone.

Ans had no limit on how long it waits for Schoolyear and no way to stop contacting Schoolyear when it is unavailable.

Impact

Between 12:18 and 12:37, the platform experienced degraded performance for all users.

Students taking a digital test secured with Schoolyear were redirected out of their test with the message "Please restart the Schoolyear session to resume the assignment". Restarting the session did not resolve this until Schoolyear recovered at 12:37. Around 1,000 students at 5 schools were affected.

Detection

On October 21st, 2026, at 12:19, our monitoring system triggered an alert indicating that the platform had become slow or unresponsive.

Response

On October 21st, 2026, at 12:30, a status message was posted to inform users of degraded performance. The technical team investigated the issue and confirmed that the outage at Schoolyear caused the degraded performance.

Recovery

On October 21st, 2026, at 12:37, Schoolyear resolved their outage and the platform recovered. A fix will be deployed that limits how long Ans waits for Schoolyear and temporarily stops contacting Schoolyear after repeated failures. This way an outage at Schoolyear will no longer occupy the capacity of the platform.

Timeline

21st of October, 2026

• 12:18 - Schoolyear starts responding slowly and with errors. The platform experiences degraded performance.
• 12:25 - Schoolyear starts investigating an outage of their production servers.
• 12:30 - Our monitoring system triggers an alert and a status message is posted to inform users of degraded performance.
• 12:32 - The status message is updated to inform users that the platform is available again.
• 12:37 - Schoolyear responds normally again. Students can continue their digital tests.
• 12:41 - Schoolyear confirms that their outage is resolved.

Reflection

The incident occurred when an outage at Schoolyear caused Ans to wait for answers that were slow to arrive. Because every page in a Schoolyear-secured digital test depends on Schoolyear, an outage at Schoolyear affected the performance of the whole platform, including for users not taking a digital test.

Ans should remain responsive when an external service is unavailable. The fix limits the impact of a Schoolyear outage to the digital tests that depend on it. The technical team has reviewed the other integrations with external services and is applying the same protection to them.