Articles█
On building products that matters in the AI era.
17 June 2026
A PRD says what to build and why. A spec is what gets built. Why the PRD format is dying, why the function is moving into the spec, and which an agent needs.
A brilliant solo spec workflow vanishes the moment a second person needs in. Why solo specs break on a team, and what survives a handoff.
Spec-driven development puts the spec at the centre of AI coding. What makes a good one, why specs drift, and how a spec differs from a PRD.
AI coding agents read the spec and build something else. Why following the spec doesn't stick, why instruction files don't fix it, and what does.
Specs drift because the real decisions leave the document. Why spec drift happens, why keeping the doc updated never works, and what stops it.