Just an introduction: Currently I'm using runsit as an alternative for supervisord and I'm happy with it so far. Stdout and stderror of the processes can be queried with a very simple HTTP interface.
Runsit watches a config directory for any changes and applies them immediately. Config files are in json format.
Mind sharing a (lightly commented) config? I've been using Supervisor to run my Go services for a long while (the built-in log rotation is one of the big attractions) but keen to try alternatives. I never found mmonit and other alternatives to be as comprehensive as Supervisor.