Amalgam8 supplies us a Registry, and a Controller, via which it implements the Service Discovery, and Service Proxying that we make use of in our core services.
We have started adding event driven processing to the Game On core services, and Kafka (also used by Amalgam8) is our chosen Publish/Subscribe solution.
Etcd was added to simplify configuration management. There are many ways to slice this particular onion, but the important thing for us was being able to see the configuration attributes used, and in some cases shared, by our core services in a central place.
The configuration attributes stored in etcd are environment-specific: different values are provided for different deployment stages using isolated etcd clusters. Etcd is not used when developing locally, we instead rely on local env files injected via Docker Compose.