I have never written it down, but it's very simple. I don't use any external libraries. I converted the input databases to lisp and compiled them in, and the output is simple postscript. When I want to deploy I dump a core with the compiled functionality, then run sbcl with that core. At some point I was using hunchentoot[1] to provide an http point of entry (great library, as all the ones written by Edi Weitz) but I am not bothering anymore, as most of the processing time is consumed by ghostscript and convert in the post-processing of the images.

[1] https://edicl.github.io/hunchentoot/