Segregation of duties, approval ceilings, duplicate rejection, period locks and reversal-only corrections — enforced in the code path rather than described in a policy.
A creator cannot approve their own bill, an approver cannot exceed their ceiling, and a closed period refuses to accept an entry.
Accruals that reverse themselves on day one, prepaid amortisation and depreciation posted a period at a time, all idempotent.
Continuous agents raise missing accruals, outliers, duplicates and unrecognised revenue while there is still time to act.
Each of these is a product page describing code that exists.
A seeded company, a close in progress, and every number computed by the engines.