I don’t know how much validation the code does, but every single number in your tax forms is related to another by some statement in the law, and these change c

I don’t know how much validation the code does, but every single number in your tax forms is related to another by some statement in the law, and these change constantly. Validating them means codifying every single rule. Germany figured this out a while ago and built a rule engine with GUI and small DSL where the lawyers can input tax rules to the database - meaning better code and you can emit for any platform. It’s called ElsterRules (Elster is the online tax filing program) and runs even in your browser... I wonder if there’s something similar in other countries.