This provides a lot of good information. Thanks for sharing it!

Two small tweeks I'd like to suggest, if I may?

I'd recommend replacing flowcharts with Business Process Model and Notation (BPMN) diagrams, however.

https://en.wikipedia.org/wiki/Business_Process_Model_and_Notation

These standards-based diagrams look a lot like flow charts but are also executable using a workflow engine like Camunda BPM, i.e. the diagram IS the process, not just a representation of the process. When the diagram changes, so does the process -- self-documenting.

It's also possible (and fairly common) to incorporate event-driven capabilities and microservices in a layered (n-tier) technical design, rather than having to choose between them.