Some Odoo customizations carry across an upgrade almost untouched and some need real work. Which one you get is decided the day it is built, not the day you upgrade.

Configuration, Studio, or a custom module? The three ways to change how Odoo behaves are not interchangeable. The real trade-offs on upgrade risk, testability, and who maintains it.

Most Odoo customization requests are process problems wearing a software costume. How to tell the difference, what customizing really costs long term, and when to change the process instead.