What building really involves
A usable ledger needs double-entry accounting, bank feeds, reconciliation, invoicing, bills, reporting, user permissions and audit trails, all maintained as regulations and bank integrations change. Each of these is a product in its own right, and clients expect them to work every day.
Beyond the first release, there is hosting, security testing, backups, support and a steady stream of fixes. For most firms, that ongoing commitment pulls attention away from advisory and bookkeeping work, which is where the firm actually earns its reputation.