Typst: A Programmable Markup Language for Typesetting [pdf] - https://news.ycombinator.com/item?id=34423590 - Jan 2023 (53 comments)
Typst: Compose Papers Faster - https://news.ycombinator.com/item?id=32209794 - July 2022 (30 comments)
Typst: Compose Papers Faster - https://news.ycombinator.com/item?id=32205005 - July 2022 (1 comment)
Also
Writing an Incremental Typesetting Engine - https://news.ycombinator.com/item?id=33215909 - Oct 2022 (0 comments, but looks interesting)