A UK digital bank

BankingDigital Bank

Preparing core banking for a hybrid cloud, "zero data centre" future

From static, data-centre-centric platforms to a hybrid cloud strategy with elastic capacity and controlled risk.

Platform & ArchitectureCloud & Payments

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Defined hybrid cloud target architecture and migration patterns

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Introduced burst capacity for peak processing without overprovisioning

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Improved resilience, observability and change safety for core services

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Created a roadmap from monolithic workloads to domain-aligned services

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Engineering Facets

Zero DowntimeCloud NativeReversibilityCompliancePlatform Thinking

Expertise

Cloud Transformation Engineering

Accelerators

Cloud Native Foundation Runtime Integrity Engineering Reversible Engineering Continuous Delivery

Capabilities

Platform Engineering

“The path to cloud isn't lift-and-shift. It's domain-driven decomposition with reversible deployments and incremental migration patterns.”

Context

The bank's core systems still ran primarily in on-premise data centres. Demand patterns were spiky: peaks at month-end, product launches and regulatory reporting windows. Hardware-based scaling and inflexible change windows were constraining growth and slowing transformation. The bank wanted to move towards a hybrid cloud model: using cloud elasticity for suitable workloads while retaining control and compliance for sensitive functions.

The Challenge

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Build a credible hybrid cloud strategy that regulators, risk and operations could all support
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Avoid "lift and shift" that simply relocates problems to the cloud
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Enable burst computing for certain workloads without compromising data residency and control
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Protect the integrity of core processes during migration

Our Approach

Hybrid target architecture definition

Classified workloads by sensitivity, volatility and integration needs. Identified candidates for cloud-native refactoring vs. controlled encapsulation.

Domain-aligned breakout

Used domain-driven techniques to separate capabilities (e.g. product, pricing, risk, reporting). Created integration facades to allow gradual detachment from the mainframe/core.

Elastic and burst computing patterns

Designed patterns for offloading intensive analytics and reporting workloads to cloud. Emphasis on reversible deployments, so changes could be backed out safely if required.

Operational and observability uplift

Introduced platform-level telemetry across both on-prem and cloud components. Implemented structured change rollout with feature flags and progressive exposure.

Engagement Timeline

Assessment & Classification

2 months

Classified workloads by sensitivity, volatility and integration needs. Identified cloud-native refactoring candidates vs. controlled encapsulation.

Domain Breakout Architecture

3 months

Used domain-driven techniques to separate capabilities and created integration facades for gradual mainframe detachment.

Elastic Patterns & Delivery

3 months

Designed and validated burst computing patterns for analytics and reporting workloads with reversible deployment strategies.

Operational Uplift

2 months

Introduced platform-level telemetry across on-prem and cloud, with structured change rollout and progressive exposure.

Outcomes

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A hybrid cloud roadmap that both technology and risk stakeholders could support.
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Reduced reliance on "heroic capacity planning" for peaks through elastic processing.
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Lower risk of large cutovers thanks to incremental, domain-driven migration patterns.

Technologies & Patterns

Hybrid cloud architectureDomain-driven designFeature flagsProgressive deliveryPlatform telemetryMainframe integration facades

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