In case they are reading this, here's what I liked and what I think can be approved upon:
LIKED:
- Besides the interactive examples, it looks like you stuck to using standard web fonts instead of loading some bullspit Typekit or Google Font Loader thing. Thumbs up!
- Thanks for dark mode!
- Overall the design is minimalistic. Thanks for not trying to impress everyone with "modern" design or l33t JavaScript skillz.
- Thanks for keeping MDN alive!
THINGS THAT CAN BE IMPROVED:
- The branding is less distinctive than it was before. It's definitely not bad, but the bold monospace "MDN" was more distinctive and made me feel like I wasn't on some rando site. (In fact, that logo still is visible at the footer of the page.)
- I'm not the biggest fan of the 3-column layout. Again, it's not bad, but I think I could totally do without the right-hand column and give the main content more horizontal space. Remember that your site is for developers, and I think most developers are fairly pragmatic about how much content they want to see on-screen at a time.
- The left-hand column is a bit weird. I'm not sure how much of a benefit the scrollbar provides and it also seems to jump when you get to the bottom of the page, which is distracting.
- As others have mentioned, the compatibility table seems nerfed. Definitely don't get rid of it, but I think making it more useful would have gotten more people a positive view of the new page design. If that feature provided a little more info so that I only resorted to caniuse.com 1/3 of the time as opposed to 2/3 of the time, that'd be a good win.
- Remove the hover effects for the top menu items in favor of revealing details on hover/click. Hover is the devil even on desktop; I hate it when I casually drag my cursor from the URL bar down to the page and suddenly some page element appears and covers up what I'm trying to look at.