Backend Basics (2026)

Backend development is about responsibility, not frameworks.

What Backend Owns

• Authentication and authorization
• Business rules (what is allowed vs not)
• Database reads/writes
• Validation and security
• Error handling and reliability

APIs Explained Simply

An API is a contract:

• Input comes in (request)
• Logic runs (processing)
• Output goes back (response)

Common Beginner Mistakes

• Trusting frontend inputs
• Skipping validation
• Not handling errors
• Mixing business logic into UI

Key Takeaway

Frameworks change. Backend principles don’t.