I Built a Free Astrocartography Calculator with Next.js — Here's the Full Story

Most astrocartography tools online are either locked behind a $20/month paywall, built on Flash-era technology, or so cluttered with ads you can barely find the actual calculator. As a developer who stumbled into the world of astrology charts, I kept thinking: someone should just build a clean, free one. So I did. Here's the honest story of how I built Astrocarto — the technical decisions, the unexpected hard parts, and what I'd do differently. What Even Is Astrocartography? Quick background for the non-astrology crowd (which is probably most of you): Astrocartography is a technique that takes the positions of planets at the exact moment you were born and projects them as lines onto a world map. The idea is that certain locations carry specific planetary energies for you — your "Venus line" might run through Paris, your "Mars line" through somewhere you'd rather avoid. Whether or not you believe any of that — the math is genuinely fascinating. We're talking about: Calculating precise p