Dates:

Thursday, April 16th 2026, 00:00 UTC – 09:15 UTC

What happened:

Live and automated tests on iOS 17.0 simulators failed to start in both the EU and US-West data centers. Customers running tests on iOS 17.0 Intel-based simulators were unable to execute their tests for approximately 9 hours.

Why it happened:

A deployment introduced an incompatibility affecting iOS 17.0 on Intel-based infrastructure. The issue was not caught prior to release due to insufficient post-deployment test coverage for that specific simulator configuration.

How we fixed it:

We performed a rollback to the previous deployment, which restored full iOS 17.0 simulator functionality.

What we are doing to prevent it from happening again:

We are reviving and expanding automated post-deployment tests to cover a broader range of simulator configurations, including legacy Intel-based iOS versions, to catch incompatibilities before they reach production.