shared · easy
SCREAMING_SNAKE_CASE
Uppercase words separated by underscores — e.g. API_KEY, MAX_RETRY_COUNT (also called CONSTANT_CASE).
Where you see it
Used for true constants and especially environment variables (DATABASE_URL, OPENAI_API_KEY). Config and secrets tooling almost always expects this shape.
Why it matters
Misnamed env vars fail silently at deploy time. AI and web services lean heavily on SCREAMING_SNAKE_CASE for keys and feature flags.
Interview angle
Ask where you’d put a secret vs a code constant, and why env vars use SCREAMING_SNAKE_CASE while app variables usually do not.
Tags: naming, javascript, python, ruby