Satoshi Standard

Real-time dashboard tracking Bitcoin purchasing power across currencies. Live price API with a full Vitest unit-test suite covering all conversion logic.

No clean tool existed for tracking Bitcoin's real purchasing power across currencies in one place. The technical constraint was making a live-data UI stay responsive when price feeds update constantly, and keeping the conversion logic correct when the data model changed.

React and Tailwind for the live UI. Vitest to pin the conversion logic so refactors can't silently break numbers users depend on. No heavyweight state library, co-located state was enough.

Identified the product gap, scoped the feature set, and shipped it. Pushed all derived math into selectors so only cells with changed values re-render. The test suite runs against pure conversion functions so coverage is fast and the maths stays trusted across iterations.