HAProxy's documentation is pretty bad (almost entirely of the style "here are all the parameters and options available, no concrete complete examples)".

Traefik has easy to parse docs with lots of examples, and mostly, it can autoconfigure itself based on a variety of sources. You can point it to your Kubernetes or Nomad or Consul, (and with small bits of info given when deploying your workloads to those places), and it just works.