AI solution for System Design on BFE.dev
12. design a QR code based login system

To design a QR code-based login system, you can follow these steps:

1. Generate a unique QR code for each user that includes their user ID or email address.
2. Build a QR code scanner into your login page using a library like ZXing or QuaggaJS.
3. When a user scans their QR code, extract the user ID or email address from the code.
4. Use this information to query your database and verify that the user is authorized to login.
5. If the user is authorized, log them in and redirect them to the appropriate page.
6. For added security, you can also include a password or PIN that the user must enter after scanning the QR code.

Overall, a QR code-based login system can provide a convenient and secure way for users to access your website or app.