Crafting Great APIs with Domain-Driven Design by Fabrizio Lazzaretti @ Spring I/O 2026

This talk at Spring I/O 2026 focuses on the importance of aligning APIs with the business domain they serve, highlighting that many API failures stem from a disconnect between technical design and business needs. The speaker presents a practical methodology for applying Domain-Driven Design (DDD) to API development, starting with Domain Stories to capture workflows and creating a Visual Glossary for a shared Ubiquitous Language. The approach includes using the API Product Canvas to define clear boundaries and consumer focus for APIs, and addresses both synchronous and asynchronous API design. The session covers a comprehensive design journey, integrating business modeling, capability mapping, Domain Storytelling, Event Storming, and API specifications using OpenAPI or AsyncAPI, with enhancements from LLMs.