For "integrated" stuff, their stance is "UI Must Work". Tracing down the requirements, here:
https://design.home-assistant.io/#concepts/home
https://developers.home-assistant.io/docs/configuration_yaml_index
https://github.com/home-assistant/architecture/blob/master/adr/0010-integration-configuration.md
...usually there's YAML kicking around the backend, but for normal usage, normal users, the goal is to be able to configure all (most) things via UI.
I've had to drop to YAML to configure (eg) writing stats to indexdb/graphana vs. sqlite (or something), or maybe to drop in or update an API_KEY or non-standard host/port, but 99% of the time the config is baroque, but usable via the web-app.