Online Order — Food Ordering That Stays Correct Under Load
View completed workgithub.com
What it does
A food-ordering app for customers and kitchen staff: limited daily dishes, live order tracking, and a kitchen board that updates the moment a payment clears.
Customer order tracking
The hard part: staying correct when many people act at once
Limited stock is never oversold — in a test, 40 customers race for 10 portions and exactly 10 orders go through.
A retried checkout never creates a second order — 20 concurrent retries of the same checkout produce one order.
A duplicated payment webhook never charges twice — the same payment callback arriving 5 times at once is applied once.
Every cent moves through a double-entry ledger, so what each restaurant is owed always adds up.
Live updates go from the database to the customer and kitchen screens as soon as an order changes.
Each of these guarantees has an integration test against a real PostgreSQL database, run in CI on every change.
Stack: Spring Boot 3 (Java 21), React, PostgreSQL
Personal project. The restaurants are fictional and payments go through a simulated card processor.
0 likes · 4 views · Sep 26, 2026
A food-ordering app with a live kitchen board that never oversells stock, never creates a duplicate order and never charges twice — each guarantee tested against a real PostgreSQL database.
