While the banking sector looks to become more streamlined and competitive, it continues to grapple with growing complexity. Enhancing the 24/7 customer experience, regulations, mergers and acquisitions, new technology and aging platforms are now part of everyday challenges.

It’s clear many financial institutions see the need for their core banking solutions, currently sitting at the centre of their operations, to rise to these challenges and meet changing expectations. The cost and complexity of achieving this with legacy core banking systems means instead banks are looking to migrate products to more contemporary platforms.

  • The coexistence approach

    Core banking transformation needs to be done in a risk managed and controlled manner that caters for an ‘always on’ customer experience, and so banks are looking to a streaming based data migration approach, also known as ‘coexistence’, to enable it.

Customer-centric core banking migration

Many financial services institutions are looking to decommission, consolidate and upgrade their core banking platforms, replacing them with more responsive, flexible, secure and simple technology.


During this process, we often see three main points of complexity:

Customers expect 24/7 servicing

Gone are the days of switching off services to upgrade data technology over a weekend, only to turn them back on again on a Monday morning.

Migrations must be seamless – continually happening in the background, while service excellence and unceasing transactions continue in the foreground.

Multiple banking product relationships

Customers have multiple banking product relationships, and multiple systems support them.

Practically, not all products can be transitioned to new platforms at once. As a result, customer data will often need to exist in multiple places simultaneously, with no impact to the consumer, and therefore increasing the migration’s complexity.

Hollowing out the core

The desire to manage core banking transformation risk by ‘hollowing out the core’.

In many instances, banks are gradually and methodically moving product functions away from the legacy core platform to new technologies, rather than doing it all at once.

This requires a strategic approach, comprehensive controls and automated reconciliations that allows for systems, and the data they are custodians of, to coexist.

Coexistence as a preferred migration pattern

  • Coexistence (the concurrent running of legacy and target core systems) is an approach to manage this complexity.

    But from a data migration perspective, maintaining the continuous operation of critical business processes requires legacy and target system syncing, and robust, repeatable control over changes and migrations.


Coexistence has applications across all aspects of core banking ledger migrations and is set to become a preferred migration pattern for high volume, multiple release, customer-centric transformation initiatives.

KPMG Powered Data has designed an innovative data migration approach to mitigate the specific data migration challenges associated with coexistence.

How KPMG enables coexistence in banking

KPMG Powered Data developed a coexistence data migration pathway by adapting our proven Powered Data method and principles to cater to the requirements of a coexistence approach.

This coexistence data migration pathway allows us to orchestrate migrations across legacy and target core banking and customer servicing systems for multiple financial products with different journeys, business rules and technical constraints.

Our coexistence data migration pathway includes robust automated controls, traceability, and auditability of customers and their data through the end-to-end migration journey. It utilises an iterative approach to allow early testing, learning and therefore de-risking of delivery.

  • "KPMG Powered Data has refined and standardised our coexistence data migration pathway to deliver a solution specifically for financial services. This solution addresses the challenges associated with core banking transformations and enables banks to deliver best-in-class digital experiences for their customers."

    Brendan Gialouris
    KPMG Powered Data

KPMG Powered Enterprise Data solutions

KPMG has a business-first attitude – our Powered Data Migration approach keeps customer and business outcomes top of mind, while mitigating risk and ensuring the completeness and accuracy of the task.

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