Building a Smart Parking IoT App

A deep dive into designing SmartPark, a real-time IoT parking management system, using Hexagonal Architecture (Ports & Adapters) instead of microservices. Architecture comparison, IoT stack choices, and why frameworks like NestJS make hexagonal natural. The Problem: 72 Hours to Detect a Dead Sensor Imagine a city with 500 parking sensors embedded in the ground. One of them dies. Nobody notices for 72 hours. Meanwhile, the dashboard shows a spot as "occupied" that's been empty for 3 days, agents are dispatched to phantom problems, and citizens can't find parking. This is the reality of most municipal parking systems today. SmartPark is an independent application built to fix this — real-time occupancy tracking, automatic anomaly detection, and field agent dispatching, all powered by IoT sensors and designed with Hexagonal Architecture. But the interesting part isn't what it does — it's how it's architected, and why we chose hexagonal over microservices. What is SmartPark? SmartPark