Validate Request Payloads at the API Boundary

A lot of “random” backend bugs start because invalid data entered the system too early.

Do not wait until database save time to discover that a field is missing, the type is wrong, or the payload shape changed.

Validate request data as soon as it enters your API.

Why this matters:

• Bad data fails fast
• Error messages become clearer
• Business logic stays cleaner
• Debugging gets much easier

Example:
Instead of directly using req.body in your service, first validate:

• required fields
• data types
• allowed values
• nested object structure

Good rule:
If the client sends data, the server must verify it.

This is one of those habits that feels small at first, but saves a lot of production pain later.