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 Stack React (Create React App + CRACO) for the frontend 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. The Architecture (Simplified) Mistake 1: Not Designing the Cache First Mistake 2: Blocking Operations in an Async Framework Mistake 3: Treating SEO as an Afterthought usd-to-eur, /eur-to-gbp, and so on — around 380 pages total. Generating these with a build-time Node.js script that runs during Vercel deployment was the right solution, but retrofitting it into an existing app took significantly longer than building it in from the start would have. The Deployment Reality What the App Does Now Live forex rates for 60+ currencies, updated every 10 minutes The gold and silver charts section pulls XAU/USD and XAG/USD data, caches it, and renders price history in a way that updates on page load without a full reload. What I Would Do Differently One More Thing FloatForex.com — live forex rates, real-time gold prices, and free financial tools. No account required.