Rebuilding our ledger for multi-currency settlement

We migrated from a single-table balance model to event-sourced entries. The post covers idempotency keys, reconciliation jobs, and why we kept humans in the loop for exceptions.

Money movement is unforgiving — we want engineers who find that motivating, not stressful. You'll work on systems where correctness matters, incidents are learning events, and on-call is shared fairly across the team.