What common mistake do developers make with Put and get, why does the mistake cause problems, and what is the safer approach?

What common mistake do developers make with Put and get, why does the mistake cause problems, and what is the safer approach? One recurring problem with put and get is applying it without understanding the boundary it protects. Saving user uploads directly under a public web directory without validating file type, name and access requirements. In addition, Storage APIs can write, read and inspect files through the configured disk. Safer engineering approach: keep the responsibility in the correct layer, use the framework's supported API, validate and authorize inputs, avoid hidden side effects, and verify the behavior with tests.