A staged move off a tightly coupled core — dual-run, product-by-product — so the bank could launch digital offerings without a big-bang cutover.
The situation
The bank’s deposit and customer modules sat on a decades-old core. Every product change needed a weekend window, digital channels were reading stale balances, and a full replacement had already been scoped twice and shelved. Leadership wanted modernization without putting branch operations at risk.
What we did
- Mapped the core by product and channel, then isolated the customer and deposit services that digital needed first.
- Stood up an anti-corruption layer so mobile and internet banking could read a consistent customer view while the core still posted.
- Ran a dual-run on savings products for two cycles, with recon reports the operations team signed off before each wave.
- Moved remaining products in waves tied to business calendars, not a single go-live date.
What changed
- Digital balance and transaction views no longer lagged the branch by a day.
- New savings variants could be configured in weeks rather than a quarter.
- The bank retired two tactical channel databases that had been kept ‘just in case’.