This "texture healing" technique is really impressive. It uses OpenType’s contextual alternate glyphs, usually seen in stylistic embellishments such as swash caps or ligatures. With Monaspace, they dynamically adjust the widths of characters in a MONOSPACED face, while still respecting the monospace grid. It's pretty wild. The website has a neat interactive step-by-step visualization on how it works. Also, comes in 5 faces!
https://monaspace.githubnext.com