A secure backend starts with a strict gatekeeper. Validation schemas are your first line of defense.
1Joi vs Yup
Joi is extremely powerful and feature-rich, making it the go-to for complex backend logic. Yup is slightly lighter and has a focus on being 'serializable', which makes it a favorite for full-stack developers.
2Schema Chaining
Both libraries use a fluid API. You can chain rules like .string().email().min(5).required(). This makes your validation logic readable and easy to maintain.
3Sanitization
Validation isn't just about checking; it's about cleaning. You can use these libraries to trim whitespace, convert strings to lowercase, or cast values to the correct data type automatically.
