

Sun films have been available commercially for a long while. Choose how much sunlight you want reflected (generally more in bedrooms that you generally want dark and cool, less in rooms where you want a view), and either get a professional to apply or do it yourself—it just takes a bit of soap water and effort.
Generally better to have the sun rejection happen on the outside of the window, so as little as possible energy gets absorbed.
Yeah, JSON is essentially a side effect of having JavaScript already. It makes sense that it shows up a lot of places, especially web. But just like with JS, it’s not really good, just ubiquitous.