https://servicedesign.dev/ Operational design, payment integrations, and the Foundation Layer framework. en-us Thu, 17 Sep 2026 12:00:00 GMT https://servicedesign.dev/writing/uat-is-where-integrations-go-to-die https://servicedesign.dev/writing/uat-is-where-integrations-go-to-die Tue, 25 Aug 2026 12:00:00 GMT The last mile of a payment integration has no owner, no memory, and no evidence — which is why it quietly absorbs more schedule than the build itself. https://servicedesign.dev/writing/vendor-api-evaluation https://servicedesign.dev/writing/vendor-api-evaluation Tue, 25 Aug 2026 12:00:00 GMT Every vendor API arrives as a set of promises. The gate that turns them into tested facts — auth, unhappy paths, docs versus behavior, sandbox fidelity, operational readiness — before the integration is committed to. https://servicedesign.dev/writing/the-foundation-layer https://servicedesign.dev/writing/the-foundation-layer Tue, 25 Aug 2026 12:00:00 GMT Why most problems surface at L5 and most fixes start at L1. The operational design framework behind servicedesign.dev, argued in full.