design-an-interface

Deprecated: prefer replacement named in description. Keep only for backward compatibility.

Design an Interface

"Design It Twice" (A Philosophy of Software Design): first idea rare best. Generate radical different designs, compare.

Workflow

1. Gather Requirements

• Problem? Callers? Key ops? Constraints? Hide vs expose?
• Ask: "What does this module need to do? Who will use it?"

2. Generate Designs (Parallel Sub-Agents)

Spawn 3+ agents parallel. Each radical different approach, different constraint:

• Agent 1: min method count (1-3 max)
• Agent 2: max flexibility
• Agent 3: optimize common case
• Agent 4: inspiration from [specific paradigm]

Each output: interface signature, usage example, what hides, trade-offs.

3. Present Designs

Show sequential: signature, usage, what hides. User absorb each before compare.

4. Compare

• Interface simplicity (fewer methods, simpler params)
• General-purpose vs specialized
• Implementation efficiency
• Depth: small interface hide complexity (good) vs large interface thin impl (bad)
• Ease correct use vs ease misuse

Discuss prose, no tables. Highlight divergence points.

5. Synthesize

Best design often combine insights. Ask: "Which fits your case? Any elements from others worth incorporating?"

Anti-Patterns

• Similar designs waste exercise -- enforce radical difference
• Always compare -- value in contrast
• Interface shape only -- no implement
• Ignore implementation effort in evaluation