Spec-driven development: spec before code

Spec-driven development (SDD) with a coding agent means: for a meaningful feature, you collaborate on the spec first—often a large, explicit document—before you let implementation churn begin.

Why it helps

• Gaps surface early. Ambiguity that would become “tribal knowledge” or random implementation choices gets captured while stakes are low.
• Review moves upstream. As alexop.dev argues, front-loading review at the specification phase gate reduces approval fatigue during implementation.

What “good” looks like

• The spec states functional intent, constraints, conventions, and enough domain and stack context that the agent does not need to guess.
• The spec is stored where the factory can read it—typically specs/ or your product’s equivalent (Seed).

Related

• Spec-driven development (term)
• Context engineering for agent factories