QR Attendance System

The Problem

A university needed to track attendance for thousands of students across 7 different faculties. The existing process was manual — paper registers, spreadsheets, and a lot of wasted time for instructors. The system had to handle peak load when hundreds of students scan at the same time at the start of a lecture, work on any phone without an app, give admins a dashboard to view and export records, and stay up 100% of the time during working hours.

The Solution

Hamed designed and built a complete QR-based attendance system. Students scan a QR code displayed in class — it opens in their browser, records attendance instantly, and closes. Each QR code is time-limited to prevent cheating. Instructors and faculty admins log into a dashboard to see records, generate reports, and manage the system. On the backend, Hamed built a hybrid verification pipeline: fast in-memory checks for speed, database confirmation for accuracy, and automatic fallback if any part fails. Redis caching was added to dramatically reduce database load during peak scanning times.

Technologies Used

• Node.js + Express.js (backend API)
• React.js (student check-in UI)
• React.js + admin dashboard (faculty control panel)
• PostgreSQL (student and attendance database)
• Redis (caching layer for peak load)
• Docker (containerized deployment)
• JWT (secure time-limited QR tokens)
• Opossum (Circuit Breaker for 99.9% uptime)

Results