[itestyourcode]

Pulsar does offer a standalone mode. It has a vertical stack of Pulsar broker, bookkeeper, and zookeeper in one process. The standalone mode also comes in a single docker image.

However, the complexity you refer to is essential in a reliable messaging framework. Use of zookeeper or any log consensus algorithm requires multiple nodes ( 3 or more) to achieve durability and high availability goal. It is out of necessity. This is actually essential complexity.

There is another messaging framework called Nats.io. It is not persistent so architecturally relatively simpler. You might want to investigate.