Inspired by Evadne Wu's Elixir London 2016 talk, I took the
opportunity during a HelloSign hackathon to explore how to improve
the overhead of using wkhtmltopdf with System.cmd.
I've created a simple C server using wkhtmltopdf's C bindings that
accepts commands over stdin.
HtmlToPdf.run\0 performs a basic benchmark. On my 2 core 2.5 GHz i7
Macbook Pro, I see approximately 30%-40% speedup.