The Most Expensive Milliseconds Are Unmeasured

Expedia Group implemented Native Time to Interactive (NTTI) metrics across mobile login screens to transform performance monitoring from a late-stage quality check into a primary engineering signal. During critical user journeys like login, performance delays are often misinterpreted as security issues rather than technical problems, making accurate measurement especially important. The team elevated screen-level performance metrics to directly influence platform decisions and engineering ownership across the organization.