Client Performance Logging

perf.js

      const {
        domLoading,
        domComplete,
        domInteractive,
        domContentLoadedEventStart
      } = window.performance.timing;

      const tti = domInteractive - domLoading;
      const dcl = domContentLoadedEventStart - domLoading;
      const complete = domComplete - domLoading;

      console.info({ perf: {tti, dcl, complete} });