Foreword

This is just a PoC, treat it as one, what is described as working works. It served it's goal :)

Requirements

Docker/local with Nats running
Docker/local with Postgress running
Change the appsettings on the NoteService.Api/ContactsService.Api ( postgress connstring + Nats IP)

PoC - Microservice with a gateway, healthchecks, 2 microservices and a quick frontend with IdentityServer in asp.net core 3.0

This is a quick PoC as i am integrating microservices ( but more complete) in another project of mine.

Some minor remarks:

But the gateway won't redirect to the path to notes ( it will go to contacts).

Frontend only gets the list/notes and is dirty :), used it to test RazorPages quickly
TagService / SchedulerService / Multitenancy is not implemented. The concepts are here though.
Using mediatR, Nats and Postgres. There was a quick PoC for integrating Nats as message broker ( and i think it works). But didn't verify it as IntegrationEvents are not yet handled.
Infrastructure layer should only contain CRUD of the Aggregate ( eg. Contact)., it contains too much now.

Chosen tech is robust, structure is awesome
using a framework that supports SAGA's ( eg. MassTransit)
more DDD ( eg. AggregateRoot, value-objects, ...)
other flow of sending events ( through the AggregateRoot)
Angular 8 or Vue 3 as admin dashboard, not for customer webapps ( = visitor oriented). Didn't like Razor Pages, but liked the minimalistic implemention. I'm wrapping Services with route-attributes for minimal code + dependencies + quick custumization for webapps connected to bff's.
removing the api layer and gateway, leaves a robust modular monolith structure and removes a lot of lag ( eg. Gateway alone is 50ms delay ) and simplifies devops complexity
Implement IdentityServer for user management, it's worth investigating