Since I started at Umbraco the link I've shared the most when helping with support issues has been a blog post article by Dennis Adofi titled "Bumping The Client Dependency Version" . It describes the method used to ensure caches are cleared for client-side assets in the back-office for Umbraco versions up to 8. There's a similar setting for Umbraco 9+ which I've recently had to look up a few times. The configuration setting is at: Umbraco : CMS : RuntimeMinification: Version and is set to a numeric value. It's documented here and, as described, uses a similar version number that can be increment manually or via a build process to ensure the same cache busting behaviour. When upgrading Umbraco to a new version of the CMS you don't need to worry about this, as the version running is already used in the hash that is generated for the cache key. But this doesn't take into account package installs, or your own custom extensions to the back-office....
Senior Developer and head of DXP at Umbraco. Previously with Zone, building solutions primarily on .NET and using Umbraco, EPiServer and Sitecore CMS. This blog is used as a repository for various tips, tricks, issues and impressions drawn from the use of technology my work and interests. All words are my own.