Critical path broken in one browser: pre-release and first 30 minutes checklists

A core flow fails in one browser or version after a build or polyfill change.

The pre-release checklist maps each item to a test class from the incident page. The first-30-minutes checklist covers detection, containment, the rollback decision and customer communication.

7 pre-release items · 7 first-30-minutes items · verified 2026-10-22

Pre-release checklist

PR-01Load the web interface on an iOS 16.2 simulator, or the oldest iOS version in the support policy, and confirm it renders past the background picture. compatibility
PR-02Parse the production JavaScript bundle against the oldest supported browser versions and fail the build on any regular expression syntax those versions reject. compatibility
PR-03Rerun the full browser matrix when a dependency upgrade changes the markdown parsing sub-dependency chain, even when the application diff is small. compatibility
PR-04Run the end-to-end test that opens the Files page in every browser listed in the support policy, not only the default test browser. e2e
PR-05Add an end-to-end test that opens a files app view that renders the rich text component and confirms the view finishes loading. e2e
PR-06Schedule a synthetic check that loads the Files page in each supported browser engine against production after every deployment. synthetic
PR-07Alert when the synthetic Files page check fails in one browser while it passes in the others. synthetic

First 30 minutes

FM-01Ask the reporting user or support for the exact browser and OS version, then reproduce on that version or a simulator.
FM-02Load the same page in other browsers to confirm the failure is limited to one browser.
FM-03Open the browser console on the affected version and record the script error, such as an unsupported regular expression.
FM-04Roll back the deployment when the core page fails in the affected browser and no tested fix is ready.
FM-05After the rollback, load the page again on the affected browser version and confirm it renders.
FM-06Tell affected users which browser and version are failing and which other browser works until the fix ships.
FM-07Post a status update that names the affected browser, the page and the time of the first support ticket.

Download the checklist

Pre-release checklist (Markdown)1.5 KB · v1.0.0
First 30 minutes checklist (Markdown)1.1 KB · v1.0.0

Only in this checklist

PR-01 is the only item among 6 published checklists in this group that relies on compatibility tests: Load the web interface on an iOS 16.2 simulator, or the oldest iOS version in the support policy, and confirm it renders past the background picture.

Questions

What should be checked before a release to prevent Critical path broken in one browser?

7 pre-release items, PR-01 to PR-07. PR-01: Load the web interface on an iOS 16.2 simulator, or the oldest iOS version in the support policy, and confirm it renders past the background picture.

Is there a rollback plan for Critical path broken in one browser?

The first-30-minutes checklist has 7 items. FM-01: Ask the reporting user or support for the exact browser and OS version, then reproduce on that version or a simulator.

What should a team do in the first 30 minutes after Critical path broken in one browser is detected?

The first-30-minutes checklist has 7 items. FM-01: Ask the reporting user or support for the exact browser and OS version, then reproduce on that version or a simulator.

Is a Critical path broken in one browser checklist still needed if deployment is automated?

Yes. Automation runs the steps; the checklist names what the tests must cover: compatibility tests, end-to-end tests and synthetic monitoring.

Which pipeline stages does the Critical path broken in one browser checklist cover?

The pre-release items map to the pre-deploy and post-deploy stages.

In what formats can the Critical path broken in one browser checklist be downloaded?

Both checklists download as Markdown files: /downloads/critical-path-broken-in-one-browser-pre-release.md and /downloads/critical-path-broken-in-one-browser-first-30-minutes.md, licensed CC BY 4.0.