snake_case because if your column ends up in a Postgres/MySQL environment your CamelCase will be become camelcase
And reading those becomes nightmares
If you are just working in Javascript/Node.js, CamelCase is the preferred option.
Depending upon how you organize the words within them (*_id, *_name, *_percent), snake case allows you to parse the column names dynamically for things like santization and formatting.
SHOUTY_CASE
Snowflake forces this, so you would also never get CamelCase w/o always quoting the column name in your queries.