How do you document service choices without locking the PRD to one provider?

How do you document service choices without locking the PRD to one provider?

A PRD should explain the user outcome. A technical decision record can explain which service currently satisfies it and why.

Describe the capability first

For narration, document supported language needs, expected input and output formats, review requirements, and acceptable failure behavior. These requirements are more durable than a provider’s endpoint name. Keep current pricing, limits, and credential setup in technical documentation with verification dates.

Record tradeoffs and replacement boundaries

Compare options using representative samples and the complete workflow cost. Document known limitations and the reason for selecting an option. Define an application-level interface around the capability so the rest of the product does not depend on every provider-specific field. This does not make switching free: output quality, timing, and error handling still need revalidation. Revisit the decision when requirements or service behavior change rather than treating the first working demo as permanent proof.