# How I Deployed a Three-Tier Web App on Azure the Right Way

A practical walkthrough of VNets, private subnets, load balancers, and the debugging moments nobody talks about. Introduction There is a version of cloud deployment that looks like this: spin up a VM, paste your code, open all ports, and call it done. It works. But it is not how production systems are built. When I set out to deploy the Book Review App — a full-stack Next.js and Node.js application backed by MySQL — I wanted to do it the right way. Three isolated tiers. Private subnets. No direct database exposure. Real load balancers. The kind of architecture you would find in an actual engineering team. This post walks through exactly how I built it on Microsoft Azure, the problems I ran into, and what each one taught me. Architecture Overview Before writing a single command, I designed the network. Here is the full architecture: Internet │ ▼ [ Public Load Balancer ] — web-public-lb │ port 80 ▼ Azure Virtual Network (bookreview-vnet — 10.0.0.0/16) │ ├── Availability Zone 1 Availabili