I want to tell you about the three mistakes I made building FloatForex.com , because the mistakes are more useful than the success story. The app itself — a real-time currency converter with live gold prices, forex rates for 60+ currencies, an AI chatbot, and a handful of financial tools — is live at FloatForex.com. It works well now. Getting there involved some genuinely embarrassing decisions that I would rather other developers not repeat. Here is what I built, how I built it, and where I went wrong. The Stack Nothing exotic here, which was a deliberate choice: React (Create React App + CRACO) for the frontend FastAPI (Python) for the backend MongoDB Atlas as the primary database and cache layer Vercel for frontend hosting Render for the backend service Cloudflare for DNS and edge protection The boring stack was the right call. Every time I considered switching to something trendier, I reminded myself that the goal was to ship a working financial tool, not to explore new technology.…