At this year's Headless Commerce Summit, Nacelle CEO Brian Anderson and Senior Sales Engineer Devin Saxon discussed Eventual Consistency and Interoperability in Headless Commerce. They compared microservice vs monolithic eCommerce architecture, highlighting that while monolithic systems are easy to start with and have ACID guarantees, they can become expensive to scale and are not ideal for bespoke services. In contrast, microservices promote best-of-breed strategy, flexibility, and the ability to quickly change tools. The three common ways to go headless were discussed, including a "Daisy Chain" approach that leaves room for eventual consistency issues, a model where all backend systems communicate independently with the frontend, and an approach using an abstraction layer and event-driven core, which Nacelle's platform is built on. This last approach addresses interoperability concerns and provides flexibility without requiring significant upfront costs.