A private company that cannot explain a system faces an awkward meeting. A public body that cannot explain one faces a parliamentary question, a freedom-of-information request and a newspaper. That asymmetry is the design brief, and it makes the public sector one of the more interesting places to build: the requirement to show the working is not friction bolted onto the project, it is the project.
So we build the record first. Which source document an answer came from, which version of the guidance was in force on the day, who reviewed it, what the system was asked and what it replied. Retrieval rather than recall, because a citation is reviewable and a memory is not. Deployment inside infrastructure the administration controls, because residency questions are usually settled by architecture rather than by contract.
And a narrow scope. The systems that work in administration are the ones that find, extract, draft and route — not the ones that decide. A caseworker keeps the decision, an official signs it, and the system’s contribution is that the file arrived complete and the guidance was quoted rather than remembered.