Subtract before you add

Build on the simplest base the change allows.

• Before adding, remove the dead code, redundant validators and stubs the change touches; report other removals instead of making them.
• When refactoring, or tempted to add an abstraction, a layer or a threaded signal, prefer deleting code to adding it.
• Delete a reference that carries nothing of its own rather than leave a stub pointing elsewhere.
• Keep each meaning in one authoritative place, so changing it is a one-place edit.
• Reach the minimum version before investing in its quality.