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.