Core banking: cloud-native re-platforming for a mutual bank

FINANCIAL SERVICES  ·  TECHNOLOGY  ·  CORE PLATFORM

The situation

This mutual bank was constrained by an outdated, outsourced core banking system under a rigid, decades-old contract. Product releases were delayed for years, customer data was fragmented, and analytics and behavioural data were largely inaccessible, locked in proprietary formats across isolated databases. Monolithic infrastructure required overnight batch processing and rigid change for even minor adjustments, preventing personalisation or open-market integration. As a smaller institution, it could not match the custom-build budgets of the majors and risked tying up scarce resources maintaining complex technology it had built itself.

Custom build

Mobile and web app

Ientity-specific features

Customer engagement layer

The work

We designed a technology playbook and a vendor-evaluation framework, and divided the re-platforming into a phased, risk-controlled journey.

  • Mapped a clean technical and commercial exit from the legacy vendor.

  • Categorised every banking function against a hybrid procurement model, to land each in the right place between custom build and rented service.

  • Structured a composable, decoupled architecture using microservices, secure delivery pipelines, and an open API gateway, with domain boundaries set through structured technical workshops.

  • Ran a four-stage filter to funnel a wide field of providers to a single verified partner on jurisdiction, functional fit, cloud-native architecture, and predictable licensing.

  • Defined a steel thread: a thin, front-to-back slice of the bank for one product or segment, stage-gated so the executive could judge progress before committing to full migration.

Buy and operate

Data platforms and cloud data lakes

Near real-time single source of truth

Procure as a service

Core accounting and ledger

Payments and clearing

Standardised back-end systems

The outcome

  • An approved roadmap moving the bank from system maintenance toward real-time, data-driven operations.

  • A verified vendor plan using as-a-service and modern core configurations to cut new-feature time from months to days.

  • A stage-gated investment model that protected capital while building a credible digital challenger.