The article doesn't appear to mention that Sentry abandoned open source. If anyone is looking for an open source fork of sentry, there is https://glitchtip.com/

Is sentry.io no longer open source? Have not followed it as closely since its so cheap.

It's source available under the BSL: https://github.com/getsentry/sentry. After four years it becomes open source (probably to prevent "AWS Elastic Error Handling service(tm)" from becoming a thing)

You can still run it for your company for free, if you feel like managing all of the infra it requires.