[charcircuit]

>and waste resources testing all of that executable code for every change

If it's a waste why is it even running those tests? That's it's own problem.

[web007]

Of course, but how do you solve that problem in the general case?

When everything lives next to everything else it's harder to draw the line around the blast radius of a change. If there was a repo boundary, that's a really easy hard constraint.