What are Docker Compose profiles good for?

You can assign Docker Compose services to profiles. Later when you are starting services, you can define which profile to use. If you pass a profile, only services that belong to a specified profile will be used.

version: "3.9"
services:
  frontend:
    image: frontend
    profiles: ["frontend"]
  healthcheck:
    image: busybox
    profiles: ["frontend"]
  phpmyadmin:
    image: phpmyadmin
    depends_on:
      - db
    profiles:
      - debug

Here the services frontend and healthcheck are assigned to the profiles frontend. You can run services from this profile by running the following command:

docker compose --profile frontend up