Put the map behind the whole app and kept it in sync both ways: every pan, filter and selection lives in the URL, so any view can be shared or restored, even with several maps on screen at once. Clustered the measurement points with Supercluster - far more than a map can draw - and shipped every component skeleton-first, so the UI never flashes empty.

Built the virtualized spreadsheet-like editor that keeps the UI instant on tens of thousands of rows, then made Playwright guard its performance in CI - so the release train never shipped a regression.

Created the white-label transit app for cities and grew it across 20 client networks. Called back by the CTO a year later to rescue it: rebuilt it with a smaller, senior team, stabilized the product, and automated multi-client QA and releases with Jenkins and Detox end-to-end tests - one QA pass switches client networks in-app. Made the app fully accessible, validated by a disability users' association.

Taught alongside client missions - and the habit stuck: reviewing code to level up a team is the part of the job I like most.