# A different perspective.

> Notes on UI review, browser evidence, and the details that make an experience work.

Canonical: https://www.diffraction.sh/blog

- [The Three Checkboxes That Moved Almost a Billion Dollars](https://www.diffraction.sh/blog/three-checkboxes-almost-billion-dollars): On 11 August 2020, Citibank meant to send $7.8 million in interest. A silent default in Oracle Flexcube sent nearly $894 million instead, and three people signed off.
- [Six People and a National Signup Flow](https://www.diffraction.sh/blog/six-people-national-signup-flow): HealthCare.gov launched on 1 October 2013. By the morning of 2 October, war-room notes recorded six successful enrolments.
- [The Button That Was Costing $300 Million a Year](https://www.diffraction.sh/blog/button-costing-300-million-a-year): Jared Spool's classic case study: a major $25B retailer's checkout forced Login or Register. The flow worked, and still cost hundreds of millions until someone watched real behaviour.
- [A code diff is only part of the picture.](https://www.diffraction.sh/blog/why-ui-changes-need-ui-review): Why we’re building a review layer for the experience on the other side of a pull request.