Core banking, payments, and settlement run on the mainframe and they cannot pause. We modernize them one slice at a time — zero-downtime cutover, transaction parity proven in shadow before a slice posts live.
Core banking, payments processing, and batch settlement commonly run as COBOL on the mainframe, with mainframe DB2 holding the system of record. These platforms were built for exactly the kind of throughput and durability banking demands, which is why they have lasted — and why a wholesale replacement is so risky. They carry posting rules, reconciliation logic, and settlement timing that the rest of the bank, and often the wider market, depends on. Modernization here does not mean swapping one packaged core for another. The posting engine, the payment rails, the reconciliation and settlement logic move slice by slice onto a modern language and an event-driven data platform that can hold a ledger's consistency and ordering guarantees — deployable in the bank's own regulated or air-gapped environment, under its own supervision and risk controls, rather than a vendor's hosting model.
Uptime, scrutiny, correctness, timing — banking has to hold all four at once, with no tolerance for a bad cutover.
A big-bang core replacement asks a bank to switch its ledger on a single night and hope every posting, every reconciliation, every settlement window still works. Slice-by-slice removes that bet entirely.
The core never goes dark. Legacy and modern run side by side until each slice has proven itself transaction for transaction.
The modern target fits the bank, not a vendor's preference. Ledger and posting services run on a modern language and an event-driven data platform tuned for high-throughput transaction and settlement loads, with end-to-end observability so every posting and reconciliation can be traced. The result is modular and testable, horizontally scalable for peak payment and settlement volume, and built on a talent-friendly stack engineers actually want to work in. It runs wherever supervision and risk policy require — public, private, hybrid, or fully air-gapped — so the modern core lives inside the bank's own regulatory perimeter.