In many cases, the login page is usable long before the pageLoad event fires. This is partly due to analytics and marketing related scripts that load late in the process but do not impact the user experience. The goal of this story is to create an accurate measurement of when the login page is "finished" in the sense that the template has rendered and the user can initiate the login process. We need this benchmark to accurately assess various performance improvements we're going to attempt on this page.
The login page represents about 10% of all page loads that take > 15s to reach dom.ready(): https://insights.newrelic.com/accounts/88178/dashboards/140558
How to create the appropriate event with the New Relic browser API: https://docs.newrelic.com/docs/browser/new-relic-browser/browser-agent-apis/report-data-events-browser-agent-api#finished
Based on various traces, I suspect that the delay between dom.ready() and the actual display of the form is mostly due to the late loading of logistration_factory.js, which is needed to render the actual form.
There should be no user visible impact from these changes.