Consumer APIs and B2B APIs have fundamentally different requirements, but most API design guidance is written for consumer use cases. The result is that many B2B APIs are poorly suited to their actual usage patterns.
B2B integrations are typically implemented once and expected to run for years with minimal maintenance. This has profound implications for API design. Breaking changes are far more costly. Documentation needs to be exhaustive. Error handling needs to be defensive.
Our experience building NordicB2B's API taught us several lessons. First, versioning strategy matters more than you think. We use URL-based versioning with long deprecation cycles, and we maintain multiple versions simultaneously for years.
Second, authentication needs to accommodate enterprise security requirements. This means supporting multiple auth methods, providing IP whitelisting, and enabling audit logging that enterprise security teams can review.
Third, rate limiting needs to be predictable and well-documented. Enterprise clients will build their systems around your limits. Changing them without warning breaks their implementations.
Fourth, bulk operations are essential. Most B2B use cases involve processing large amounts of data. APIs that only support single-record operations create unnecessary complexity for integrators.
Finally, sandbox environments need to mirror production behavior exactly. Enterprise integrators need to test their implementations thoroughly before going live, and surprises in production erode trust quickly.