1. the part of a computer system or software application that handles data processing, storage, and logic, not visible to the user
Usage: computing; often contrasted with frontend
2. the rear or less visible part of something
Usage: general use

1. relating to or denoting the part of a system that handles data processing and logic rather than user interaction
Usage: computing

Examples

• The backend of the website stores all customer data in a secure database.
• Developers spent weeks optimizing the backend to improve server performance.
• The frontend looks great, but the backend needs significant work.
• Backend systems handle payment processing without the user seeing the details.
• She specializes in backend development using Python and PostgreSQL.
• The backend infrastructure supports millions of concurrent users.