This looks very neat! I like the approach of including all data (API, messaging, database, files) as I went through similar thoughts and implementation recently with my project.

A growing pain for data integrations is data validations. The schema can be correct but the data itself may have incorrect values. I noticed you had a section about the structure and semantics of the data here (https://orbitalhq.com/docs/background/intro-to-semantic-inte...) but don't see where you could validate records using it. How do you handle these scenarios?