Quite some time ago, I encountered and amazed with some professionals that claimed to have been working with Dynamics CRM for years but still confused with the concept of solution, thus causing issues on the CRM instance that left behind and made us to fix the problems.
The previous developers left the customisations in the base solution in the dev environment and the production environment left with partially correct metadata. And also the system admin that uninstall managed solution without considering data loss, fortunately we made database backup before the uninstall.
In conclusion, basic knowledge of Dynamics CRM solution is a must for system customiser, developer and even system admin.
Below post from CRM community blog by Ben Hosking is really informational and gives the reader the essential knowledge on how solution works: