"There are no final decisions". Things will change in the future, so build in a way that allows them to be changed or reversed. You do not have control over external requirements, which are subject to change.
This can be solved by abstracted third party packages to reduce lock-in, or writing [[orthogonal]] code.
We also often don't make the best decision the first time around. Only after we try, fail, and learn, can we make a better decision.