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Website of SmartLine
Waiting in line wastes time and creates frustration for both customers and businesses. We wanted to create a smarter digital queue where people can see how long they’ll wait, join remotely, and businesses can serve customers more efficiently.
SmartLine is a simple web app that: Lets customers enter their name and order number to join a virtual line. Shows a live queue with countdown timers for each person. Allows staff to move the line forward with a single click. Updates automatically so everyone always sees the latest wait times.
Frontend: React with hooks (useState, useEffect) to manage inputs, timers, and auto-refresh. Backend: Node.js with Express to manage the in-memory queue and provide REST API endpoints (/queue, /join, /next). Communication: JSON over HTTP fetch requests from frontend to backend. Logic: Each person is assigned a random wait time; the frontend calculates their estimated finish time and displays a live countdown.
Getting the timers right: at first, countdowns would reset or show 0 because we weren’t tracking absolute end times. Handling state updates in React without overwriting or losing values. Keeping the frontend and backend in sync while refreshing every few seconds.
Built a fully working live queue system from scratch. Implemented real-time countdowns for each customer in line. Made the system simple but flexible, with clean separation between frontend and backend.
How to properly use useState and useEffect to manage time-sensitive data in React. How to design REST endpoints that keep the frontend and backend aligned. The importance of separating presentation (frontend) from logic (backend) early.
Add user authentication so people can join and check the line remotely. Store queues in a database instead of in memory (so data persists across restarts). Add notifications (text/email/app alerts) when your turn is coming up. Support for multiple queues (e.g., at different counters or locations). Polish the UI and make it mobile-friendly. Modify it so it work's in all situations.
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