How a Global Bank Rebuilt Its KYC and AML Application on Event Sourcing

A global bank's Commercial & Corporate Investment Banking group rebuilt Keystone, the application behind its KYC, AML, and due diligence work, on event sourcing. It runs on a five-node, highly available cluster, with field-level encryption and crypto shredding for personal data.

Introduction

A global bank’s Commercial & Corporate Investment Banking group set out to modernize Keystone, a critical application in its Customer Lifecycle Management practice. Keystone supports the bank’s regulatory work, including:

Customer Due Diligence (CDD)
Know Your Customer (KYC)
Anti-Money Laundering (AML)

It also supports the bank’s lines of business through their digital transformation: Commercial and Corporate Investment Banking, Payment Systems (credit cards), Insurance, and Investment.

The Challenge: Modernizing Keystone Without Losing the Audit Trail

The bank set clear requirements for the new Keystone:

A 100% reliable audit log of every change to a business entity
A purpose-built event store and message router, with events published on every state change
Independently scaling reads and writes (CQRS)
High availability through clustering across multiple nodes and locations
Encryption of data at rest and in transit, plus access controls for authentication and authorization
Location awareness for geographically distributed teams, and support for multiple bounded contexts

The Solution: An Event-Sourced Keystone, With Crypto Shredding for GDPR

The bank rebuilt Keystone on Axon Framework, replacing an incumbent third-party database and message broker combination. After evaluating several alternatives, it standardized on Axon Server Enterprise Edition with Axon Data Protection.

One event store and message router

With event sourcing, every change to a customer record is stored as an event, so the audit log is the data itself, not a copy. Axon Server acts as both event store and message router, which made the bank’s environments easier to set up and maintain.

Clustered for high availability

The bank runs a five-node Axon Server cluster in Kubernetes for failover and resilience, with SLA-backed support.

Crypto shredding for personal data

An immutable event store raises an obvious question: how do you honor a GDPR or CCPA “right to be forgotten” request? The bank uses field-level encryption with crypto shredding (cryptographic erasure). Deleting a person’s key makes their personal data unreadable, while the rest of the event history stays intact.

The Role of Axoniq

During the proof of concept phase, Axoniq provided in-house guidance, training, code review, and support.

“Working with Axoniq in supporting the bank on Keystone was a wonderful experience. The event-driven expertise of the founders and Axoniq team was pleasantly overwhelming. We were in great hands throughout the evaluation period all the way into production rollout!” - Consultant & Solutions Architect, global bank

See how Axoniq supports KYC, AML, and audit-heavy systems in financial services, or talk to a solution architect.