The Power Automate designer had a single User Experience for many years, until about 2 years ago, Microsoft released a new version of the designer with added functionality. You would have to opt in to use the new designer and the flow would allow you to edit it in the Classic or New Interface.
On February 8th, Microsoft announced the General Availability of Single Page Applications (SPAs) for Power Pages. Starting with version 9.8.1.x and later user will be able to build modern, client-side rendering web sites using React, Angular or Vue and deploy them directly to a Power Pages web site using the Power Platform Command Line Interface (CLI).
Today, February 5th, the Microsoft Power Platform team announced the General Availability of Code Apps in Power Apps. This new functionality allows developers to build custom applications within their Power Apps environments.
