The product manager's guide to API platforms

APIs are often treated as an engineering detail. For platform businesses, they are the product — and developers are the customers.

Know who the API is for

Internal teams, partners and public developers have very different needs. Decide who you are optimising for before you design endpoints.

Developer experience is the interface

Documentation, sandbox environments, error messages and onboarding time are the API equivalent of UX. Measure time-to-first-successful-call.

Version deliberately

Every breaking change costs your partners money. A clear lifecycle — design, release, deprecate, retire — protects trust and your roadmap.

Measure adoption, not endpoints

Count active integrations, call volume by use case and partner retention. The number of endpoints shipped tells you very little.