YAML: probably not so great after all
Don’t get me wrong, it’s not like YAML is absolutely terrible – it’s probably better than using JSON – but it’s not exactly great either. There are some drawbacks and surprises that are not at all obvious at first, and there are a number of better alternatives such as TOML and other more specialized formats. Personally I’m not likely to use it again when I’ve got a choice.
One good alternative might be to just use commandline flags.
If you must use YAML then I recommend you use StrictYAML, which removes some (though not all) of the more hairy parts.
The above is the conclusion Martin Tournoij reaches in his article YAML: probably not so great after all