Jennifer Rexford

Built World

Expert commentator on internet architecture

On February 16, 2026, a misconfigured routing update at Cloudflare's Ashburn data center cascaded across the internet, taking down X for three hours and degrading AWS's largest region. Thousands of other websites went down too. The error took 40 minutes to identify but four hours to fix because corrupted routing tables spread to upstream providers.

Updated May 29