Developing Layers of Cake instead of Slices of Cake in your software engineering projects
In the microservice architecture where you have a collection of APIs that consume each other directly or via pub/sub approach, and Front End components that consume APIs, it is important that you execute the development of your features/epics and user stories in a fashion that allows product management, you and stakeholders to see progress and journeys working very early (Sprint 1 or 2).
API contracts need to be negotiated from day 1 and the stubbed version of APIs need to be developed and as the development progresses from sprint to sprint, these APIs will start to form shape.
As for the Front End, you need to have a website working (journeys working) from Sprint 1 and that website maybe using a lot of stubbed versions of APIs which is totally ok. It will evolve as you progress from sprint to sprint and less and less of functionality will be stubbed out.
Conclusion: Develop layers of the cake instead of slices of the cake.