Zero drift, zero exceptions, zero excuses.
The neobank was doubling every eight months. That is a wonderful problem until the auditor arrives. Reconciliation drift across three payment rails was running at 0.4% per day and compounding. Regulators in two target countries had frozen the expansion pending a clean ledger.
We built the new ledger in Go on Postgres, append-only, with logical-time ordering that survives clock skew and partial partitions. Every event is a fact; no fact is ever mutated. The reconciliation engine tails every rail in real time and refuses to fall behind.
For six weeks the new ledger ran in parallel with the legacy one, taking the same inputs and producing balances the auditor could diff line-by-line. When the diff hit zero and stayed there for three consecutive audit windows, the legacy system was retired.
SOC 2 Type II passed on the first audit. Regulatory approval landed for four new countries within a quarter. Reconciliation drift over the first 180 days: zero, to the cent.
“Our auditors stopped asking us questions. That is the highest praise.”
Meridian now underwrites every product line the bank has launched since — including two credit products the old ledger could never have supported.