If you want to do something like this in Ruby, have a look at HexaPDF - https://hexapdf.gettalong.org/ https://hexapdf.gettalong.org/ - which provides a full-bl

If you want to do something like this in Ruby, have a look at HexaPDF - https://hexapdf.gettalong.org/ https://hexapdf.gettalong.org/ - which provides a full-blown implementation for reading and writing PDFs and is quite mature already (n.b. I'm the author). It is licensed AGPL+Commercial but if you just use it for yourself, this does not matter as you can use the AGPL.