Testlify runs as a suite of four separate applications, and each one had been rebuilding the same buttons, forms, modals, and tables its own way. That meant the same work done four times and a UI that drifted out of sync between products. I made the case for a single shared component library instead of per-app duplication, then built and shipped it.

What I built

The decision: Argued for consolidating UI into one library rather than letting each app keep its own copy — weighing the upfront cost against the drift and duplicated effort we were already paying. Once it was agreed, I owned the build.
Stateless by design: Kept the components stateless and presentational, so they carry no app-specific logic and drop cleanly into any of the four products. Each app wires in its own data and behavior; the library just owns how things look and feel.
Shipped as a private npm package: Published it as a versioned private npm package, so every app pulls the same components through a normal dependency and picks up fixes and improvements with a version bump — no copy-paste, no forks.

Why it mattered

Building UI once and reusing it across all four apps cut feature delivery time by roughly 30% — teams stopped rebuilding the same primitives and started composing from a shared set. It also gave the whole suite a consistent look, since a change in the library lands everywhere at once instead of being reapplied by hand in four places.