If my program needs more than a couple arguments, I prefer a YAML configuration file. I usually try to enable environment variable substitution in that file. Th

If my program needs more than a couple arguments, I prefer a YAML configuration file. I usually try to enable environment variable substitution in that file. This makes configuration more natural when/if the program is run in a container (you don't need to volume-mount a file); and it gives the user flexibility in how they configure the program. To each their own, I suppose.