It's a short and pretty ugly Python script that reads a directory of text files and plugs them into Jinja2 templates (virtually all of the actual logic is in the templates). I find myself using this pattern pretty often because I am very much not a web developer and find most SSGs to be insufferably complicated for my use cases.

When I write new posts, I use a shell script that runs them through aspell, then runs the site generator, does a simple concatenation to build the email version, and calls pandoc to build the secret hidden pdf version.