design-an-interface

Generate several radically different interface candidates in parallel, each under a distinct constraint such as minimal method count or maximum flexibility. Then compare them on simplicity, depth, and ease of correct use before committing to one.

Design It Twice, from A Philosophy of Software Design, states that your first design idea is unlikely to be the best. It recommends producing multiple fundamentally different designs and comparing their trade-offs before choosing.

Each sub-agent receives a different design constraint, such as minimizing method count or optimizing the most common case. This forces genuinely divergent proposals rather than minor variations of one idea, making the comparison meaningful.

A deep module has a small interface hiding significant internal complexity, which is desirable. A shallow module has a large interface over thin implementation, which adds learning cost without hiding much complexity.

Skip it for trivial modules with obvious shapes or when an established codebase pattern already dictates the interface. The technique targets genuinely uncertain design decisions, not implementation work.