ASN Bank: building a governed event streaming platform for financial services

Quick facts

Company: ASN Bank (formerly De Volksbank)

Industry: Financial Services, Banking

Partner since: 2023

Our Involvement: Enterprise-wide event streaming platform implementation with multi-availability zone deployment and self-service governance

About ASN Bank

ASN Bank is a Dutch financial services provider operating multiple banking brands across the Netherlands. As a regulated financial institution under Dutch and European banking supervision, ASN Bank operates at the intersection of two competing pressures: customer expectations for real-time digital experiences and regulatory requirements for data governance, auditability, and compliance with frameworks including GDPR, PSD2, and MiFID II.

Goals & context

ASN Bank faced a challenge common to many financial institutions: their legacy message queue (MQ) infrastructure had become a barrier to the data-driven customer centricity their business strategy demanded.

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The existing architecture created several constraints:

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Legacy MQ limitations: The incumbent message queue couldn't scale to handle the real-time data volumes required for modern analytics. Collecting and processing customer behavior data across four different banking brands remained out of reach.

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Fragmented Kafka deployments: Teams had deployed local Kafka clusters across individual applications, creating data silos with no interconnection. While this solved immediate needs, it made cross-domain data sharing nearly impossible and multiplied operational overhead.

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Maintenance burden: Three separate DevOps teams spent their time maintaining these disconnected Kafka clusters rather than delivering business value. Achieving both high volume and high resiliency proved challenging with this fragmented approach.

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Architectural inflexibility: The infrastructure didn't support the hybrid architecture ASN Bank needed. Events originating on-premise couldn't easily flow to cloud analytics platforms, and vice versa.

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This is a pattern we see repeatedly: DIY Kafka implementations succeed initially but struggle as requirements evolve. The true test isn't deployment on day one but scalability and governance in year three.

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Strategic approach

Hypothesis: A centralized, governed event streaming platform could eliminate data silos while maintaining the control and compliance posture required for financial services.

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Principles:

• Governance by design
• Self-service capabilities with centralized control
• Hybrid architecture support from the foundation
• Platform-as-a-service delivery model for internal teams

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Operating model: The platform team delivers Axual as a managed service to internal development teams. Self-service capabilities allow teams to onboard independently while governance controls ensure compliance requirements are automatically enforced.

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Implementation: building a governed streaming platform

ASN Bank recognized that their fragmented Kafka landscape wasn't a technical problem but an architectural one. Individual teams optimizing for local needs had created enterprise-wide inefficiency. The solution required consolidation, but centralization alone would simply replace one bottleneck with another.

The approach balanced two objectives: unified infrastructure for operational efficiency and self-service capabilities to maintain development velocity. Axual was deployed as a unified event streaming platform spanning multiple availability zones, replacing both the legacy MQ infrastructure and the disconnected local Kafka clusters.

The architecture supports ASN Bank's hybrid reality. Events can originate anywhere (on-premise or cloud) and be consumed anywhere, with consistent governance and security controls applied throughout. Rather than forcing a technology migration, Axual functions as the strategic integration layer. Existing applications connect via standard Kafka protocols, while the platform's connector framework handles integration with systems that cannot.

The platform serves dual purposes: as a streaming business event bus for application integration and as a bulk transport mechanism for high-volume data flows. This flexibility proved essential. Real-time customer behavior data from all four banking brands now feeds into the analytics platform, enabling automated decision-making that was previously impossible with the legacy MQ system.

Governance was designed into the platform from the start, not added later. The platform team configured role-based access controls and approval workflows aligned with ASN Bank's existing governance frameworks. Development teams can now create topics, register schemas, and connect applications through the self-service interface without waiting for platform team intervention.

This governed self-service model delivered measurable operational impact. Fifty internal teams have been onboarded to the platform, each managing their own data streams within governed boundaries. Data lineage, access controls, and schema compatibility are tracked automatically. Audit capabilities provide the transparency required for regulatory compliance without manual documentation overhead.

The architectural shift freed three DevOps teams from infrastructure maintenance to focus on business value delivery. What began as a platform consolidation became an operating model transformation: centralized control enabling decentralized execution.

Platform integration & architecture

Infrastructure:

• Amazon Web Services (AWS)
• Multi-availability zone deployment
• BiZZdesign Enterprise Studio integration

Delivery Model:

• Everything-as-code approach
• Platform-as-a-service for internal teams
• Self-service with centralized governance

Results

• 3 DevOps teams freed to focus on innovation instead of infrastructure maintenance.
• 50+ internal development teams onboarded to the platform
• 1 centralized Kafka platform replacing fragmented infrastructure
• Multiple availability zones providing automatic failover and recovery

Testimonial

"We were at a crossroads, with legacy technology preventing a solid digital transformation, and an ambitious strategy for customer centricity underlining requirements for becoming data-driven. We really needed the Axual platform to allow us to make the leap."

Roger Stoffers, Enterprise Architect, ASN Bank

Closing thoughts

ASN Bank's implementation demonstrates a principle we consistently observe: governance and agility are not opposing forces in enterprise architecture. With the right platform design, centralized control actually enables faster delivery by removing the friction of manual compliance processes.

The enduring capability ASN Bank has built is not just a streaming platform but an architectural pattern: governed self-service that scales across the enterprise while maintaining the control required in regulated industries.

Further information / resources

• Apache Kafka for Financial Services
• The Axual platform

Ready to transform your financial infrastructure?

Discuss your specific architecture requirements with our technical team. We'll share detailed insights from similar implementations at European financial institutions and demonstrate how governed event streaming can accelerate your digital transformation.

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