When a System Should Be Rebuilt

Patching can preserve a weak model longer than it deserves. The cost is not only the patch itself; it is the growing distance between what the system means and what the code now has to explain.

Rebuilding becomes a reasonable option when the constraint is structural, the desired behavior is clear, and ownership of the system is understood. Without those three conditions, a rebuild can simply replace one uncertainty with another.

The evidence to look for is repeated friction at the same boundary. If the same boundary keeps absorbing exceptions, the problem may be the model rather than the missing feature.