How I Deployed My First Production App on AWS EC2 — Every Mistake I Made

I am a third-year computer science student at IIIT Sonepat. Recently, I deployed my chat application, FastChat, on a live AWS EC2 server with HTTPS support, a domain name, and a proper Nginx reverse proxy. This blog is going to be a description of exactly what I did, how it all fits together, and what I did wrong so you don’t have to. What I Built FastChat is a REST + WebSocket chat API built with: App: Node.js, Express.js, Socket.io, MongoDB, PostgreSQL, Redis, AWS S3 (avatar storage), Jest + Supertest (testing) Infrastructure: Docker, Docker Compose, Nginx, AWS EC2, Let's Encrypt (SSL), DuckDNS (free domain) The live API is running at https://fastchat.duckdns.org Note: This URL may not always be live as I shut down the EC2 instance when not in use to avoid AWS charges. If you want to see the code instead, check out the GitHub repo at codephoenix86 . Architecture Overview Before jumping into steps, here's how everything connects: The key security decision: only ports 22 (SSH), 80 (HTT