LedgerNG

The problem

Building financial features product-by-product means re-solving the same hard problem — correct, auditable double-entry accounting — every time. That path produces subtle reconciliation bugs.

What was built

A ledger service with immutable journal entries, account trees, multi-currency support (Naira-primary), and an API that any RJT product can post transactions to without re-implementing accounting logic.

Notable engineering

• Append-only journal with balanced double-entry enforcement at the database transaction level
• Integer-kobo arithmetic throughout — no currency field is ever a float
• Idempotency keys on every posting endpoint so retried requests never double-post a transaction