How I Built a Sub-100ms Financial Calculator Suite Without Heavy Frameworks

The Problem: Heavy SPAs, bloated node_modules, and slow initial load times for simple math utility websites.

The Tech Stack: Pure Vanilla ES6 JavaScript, native CSS Grid, system font stacks, and Cloudflare Pages deployment.

Performance Results: Achieving sub-100ms load times and a 100/100 Lighthouse score.

Code Snippet: Sharing a clean calculation function for Indian currency formatting (en-IN).

Live Product Link: "You can see the production architecture live in action at [dacalculators.in]