One of the coolest features added in just announced TypeScript 3.7 is optional chaining syntax. It promises a much shorter and more readable code for dealing with deeply nested data structures. How may this nice new feature affect the performance of your project?

When we measure the page loading speed from the user’s perspective, we pay attention to the appearance of subsequent elements on the screen. Metrics such as First Contentful Paint, First Meaningful Paint and Visually Complete directly reflect what the user sees and when. But what if the page is invisible, when it loads in the background, for example in a different tab? Should we consider such views interesting for us? Don’t the collected metrics distort the results?