How do you prevent SQL Injection?

Short answer: Always use parameterized queries or prepared statements instead of string concatenation. Example with MySQL: connection.query('SELECT * FROM users WHERE id = ?', [userId], callback); Use ORM libraries like Sequelize which handle this automatically. Validate and sanitize inputs.

Real-world example (ShopNest)

A ShopNest BFF in Node.js aggregates catalog and price APIs for the React storefront.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.