There were plans to deploy Sentry in production and the beta cluster to collect Javascript errors; T226986: Client side error logging production launch (Instrument-ClientError) was done instead. See also T106913#7592741
Sentry is a realtime, platform-agnostic error logging and aggregation platform. The Sentry project includes the Sentry extension which sends MediaWiki error logs to a Sentry server, and the Buggy extension for testing error reporting, and some plans about deploying Sentry in Wikimedia Cloud VPS (project) to collect error report from community tools.
Note that since 2019 Sentry is not opensource anymore.