Learning API Styles

In this GOTO Book Club episode, Sam Newman — author of Building Microservices — sits down with Lukasz Dynowski, co-author of Learning API Styles, for a refreshingly low-level deep dive into a subject most developers think they already understand. The book deliberately starts from the network layer up — transmission modes, TCP, protocol stacks — rather than jumping straight to REST and GraphQL, because, as Lukasz explains, most API problems only become visible when you understand the substrate beneath them. The conversation covers the full spectrum: public vs. internal APIs, the Jeff Bezos API mandate moment, why treating your API as a product is non-negotiable, and why the choice between binary and textual protocols is never as obvious as performance benchmarks suggest.

The real gold comes in two moments. First, Lukasz lays out a crisp checklist for what makes a good API — audience-awareness, maintainability, efficiency, intuitiveness, resilience, security, testability, and documentation that actually matches behavior. Second, Sam shares a war story about a credit derivative system where the only way to figure out who was accessing the database was to turn off the credentials and wait for angry phone calls. The lesson: context shapes every trade-off, there's no universal right answer between REST, gRPC, WebSockets, or messaging, and the best API decision is the one that fits your situation — not the one that fits the conference talk.