On Tuesday October 27, between approximately 19:44 UTC and 21:40 UTC we experienced an intermittent issue with our web application UI which affected the ability for specific pages in the application to load correctly. The mobile app, event ingestion, and the API were not impacted by this.
Our front-end architecture uses a model that embeds different components into pages. This issue was caused by a race condition when two versions of a frontend library were inadvertently loaded into the same page by different embedded components. This caused certain pages in the web app UI to render incorrectly.
The issue was resolved by reverting to a previous version of the component.
Our teams are investigating the events that led to two versions of the library being loaded and implementing changes to prevent recurrence.