🍕 Pizza Delivery App

A production-grade, multi-tenant pizza ordering platform built with a microservices architecture. Customers can browse menus, customize pizzas with toppings, place orders via COD or Stripe card payments, and track delivery in real-time. Admins and managers get a live dashboard with instant order notifications.

Live:

• 🛒 Customer UI → [mern-pizza-app.cyou]
• 🧑‍💼 Admin Dashboard → [admin.mern-pizza-app.cyou]

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Architecture Overview

                        ┌───────────────────────────────────────────────────┐
                        │           KUBERNETES CLUSTER (AWS EKS)            │
                        │         NGINX Ingress · api.mern-pizza-app.cyou   │
  ┌─────────────┐       │  ┌────────────┐  ┌─────────────┐                  │
  │  Client UI  │──────>│  │Auth Service│  │Catalog Svc  │──> MongoDB       │
  │ (Next.js)   │       │  │ PostgreSQL │  │+ Kafka Prod │──> AWS S3        │
  │   Vercel    │       │  └────────────┘  └──────┬──────┘                  │
  └─────────────┘       │                         │ Kafka Events            │
  ┌───────────────┐     │  ┌─────────────┐  ┌─────▼──────────┐              │
  │Admin Dashboard|────>│  │  WS Service │  │ Order Service  │──> MongoDB   │
  │ (React+Vite)  │<────│  │  Socket.io  │<─│ + Stripe       │              │
  │   Vercel      │     │  └─────────────┘  └──────┬─────────┘              │
  └───────────────┘     │  ┌─────────────┐         │ Kafka Events           │
                        │  │Notif Service│<────────┘                        │
                        │  │  Nodemailer │                                  │
                        │  └─────────────┘                                  │
                        └───────────────────────────────────────────────────┘

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Repositories (Git Submodules)

Service	Repo	Tech	DB
Auth Service	pizza-delivery-app-auth-service	Node.js + Express	PostgreSQL
Catalog Service	pizza-delivery-catalog-service	Node.js + Express	MongoDB
Order Service	pizza-delivery-order-service	Node.js + Express	MongoDB
WebSocket Service	pizza-delivery-websocket-service	Node.js + Socket.io	—
Notification Service	pizza-app-notification-service	Node.js + Nodemailer	—
Client UI	pizza-delivery-client-UI	Next.js 14	Vercel
Admin Dashboard	pizza-app-admin-dashboard	React + Vite	Vercel

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Key Features

Multi-tenancy — Admins create tenants and assign managers. Every product, topping, and order is scoped by tenantId extracted from the JWT.

Event-driven cache — Catalog Service publishes a Kafka event on every product/topping create, update, or delete. Order Service consumes these events and maintains a local price cache in MongoDB — so prices at checkout are always validated locally without cross-service HTTP calls.

Stripe payments — Card orders create a Stripe PaymentIntent and return a checkout URL to the client. A webhook endpoint (POST /api/payments/webhook) verifies the Stripe signature and confirms payment before publishing the order event.

Real-time updates — WebSocket Service consumes Kafka order events and pushes them to Socket.io rooms. Managers see new orders appear in the Admin Dashboard instantly. Customers see live delivery status on the Client UI.

Notification emails — Notification Service consumes Kafka events and sends HTML order confirmation and status update emails via Nodemailer + SMTP.

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Tech Stack

Layer	Technology
Backend	Node.js 18 + Express
Auth DB	PostgreSQL (users, tenants, roles)
Catalog & Order DB	MongoDB
Event Bus	Apache Kafka
Payments	Stripe (PaymentIntent + Webhooks)
Image Storage	AWS S3
Real-time	Socket.io
Email	Nodemailer + SMTP
Containers	Docker (multi-stage builds)
Orchestration	Kubernetes — AWS EKS
Ingress	NGINX Ingress Controller
CI/CD	GitHub Actions + ArgoCD v3.3.2
Frontend Hosting	Vercel
Customer UI	Next.js 14 (App Router)
Admin UI	React + Vite

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User Roles

Role	Scope	Can Do
ADMIN	Global	Create tenants, assign managers, manage all products
MANAGER	Tenant-scoped	Manage products/toppings, update order statuses
CUSTOMER	Self	Browse menu, place orders, track delivery

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CI/CD Pipeline

Push to GitHub
    → GitHub Actions builds Docker image
    → Pushes to DockerHub (roshan798/<service>:<sha>)
    → Updates K8s deployment manifest (image tag)
    → ArgoCD detects manifest change
    → Auto-syncs to Kubernetes cluster (rolling update)

Frontend (Vercel)
    → Push to main → Vercel auto-builds and deploys

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Getting Started (Local Development)

Prerequisites

• Docker + Docker Compose
• Node.js 18+
• A running Kafka broker (see /brokers)
• PostgreSQL instance (for auth-service)
• MongoDB instance (for catalog + order services)

Clone with submodules

git clone --recurse-submodules https://github.com/roshan798/pizza-delivery-app
cd pizza-delivery-app

Run Kafka locally

cd brokers
docker-compose up -d

Configure environment variables

Each service has its own .env. Copy the example and fill in your values:

# Auth Service
cd auth-service
cp .env.example .env
# Fill in: DB_HOST, DB_USER, DB_PASS, DB_NAME, JWT_SECRET, REFRESH_TOKEN_SECRET

# Catalog Service
cd catalog\ service
cp .env.example .env
# Fill in: MONGO_URI, KAFKA_BROKER, AWS_ACCESS_KEY, S3_BUCKET

# Order Service
cd order-service
cp .env.example .env
# Fill in: MONGO_URI, KAFKA_BROKER, JWT_SECRET, STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET

Run services

# In each service directory
npm install
npm run dev

Postman Collection

A full Postman collection is included at the root:

mernspace-pizza-delivery.postman_collection.json

Import it into Postman to test all API endpoints.

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Kafka Event Flow

Topic	Event	Producer	Consumers
catalog	PRODUCT_CREATED	Catalog	Order (cache)
catalog	PRODUCT_UPDATED	Catalog	Order (cache)
catalog	PRODUCT_DELETED	Catalog	Order (cache)
catalog	TOPPING_CREATED	Catalog	Order (cache)
catalog	TOPPING_UPDATED	Catalog	Order (cache)
catalog	TOPPING_DELETED	Catalog	Order (cache)
orders	ORDER_PLACED	Order	WS, Notification
orders	ORDER_STATUS_CHANGED	Order	WS, Notification
payments	PAYMENT_COMPLETED	Order	WS

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Deployment

Backend is deployed on AWS EKS managed by ArgoCD. See pizza-app-deployment for Kubernetes manifests.

Frontends are deployed on Vercel with the following environment variables:

# Client UI
NEXT_PUBLIC_API_URL=https://api.mern-pizza-app.cyou

# Admin Dashboard
VITE_API_URL=https://api.mern-pizza-app.cyou
VITE_WS_URL=wss://api.mern-pizza-app.cyou

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Related Repositories

Repo	Purpose
pizza-app-deployment	Kubernetes manifests, ArgoCD apps, NGINX Ingress config

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Author

Roshan Kumar — GitHub