NewKernhaven 2026.4 adds Verification of Payee for SEPA payments.Verification of Payee is here.Read more →

Architecture

Strong where it must be. Flexible everywhere else.

Kernhaven is a hybrid architecture: a strictly consistent ledger at the centre, and an event-driven integration layer around it. It is the design we believe every bank needs, and the one auditors are comfortable with.

How it fits together

From channel to ledger to event.

  • Channels call a single API gateway secured with OAuth 2.0 and OIDC.
  • Core modules validate the request and post to the ledger in one ACID transaction.
  • The outbox records the event in the same transaction and publishes it once committed.
  • Consumers such as fraud, reporting and notifications subscribe independently.
Kernhaven architecture: channels call the API, the core posts to the immutable ledger, and the outbox publishes events to downstream consumers.Channels · Mobile · Web · Branch · Open BankingAPI Gateway · OAuth2 / OIDCKERNHAVEN CORE · ACIDCustomersDepositsLendingPaymentsImmutable ledgerOutboxEvent stream · Kafka / RabbitMQFraud & AMLReportingNotificationsData lake

Design principles

Four decisions that shape the platform.

ACID where money moves

Every posting is a single database transaction against a double-entry ledger. Balances are never eventually consistent.

Events everywhere else

A transactional outbox publishes every state change exactly once, so downstream systems react without slowing the core.

Modular monolith first

Modules share one deployment and one ledger by default, with strict boundaries that let you split them into services when scale demands.

Configuration over code

Products, fees and limits are versioned configuration. Upgrading the platform never means re-implementing your products.

Technical specification

Built on technology your team already knows.

Runtime.NET on Linux containers, deployed with Helm on Kubernetes
Data storePostgreSQL (primary), Microsoft SQL Server supported
MessagingApache Kafka or RabbitMQ via transactional outbox
APIsREST/JSON with OpenAPI specifications, webhooks, event schemas in AsyncAPI
StandardsISO 20022, SEPA SCT / SCT Inst / SDD, Berlin Group NextGenPSD2
SecurityOAuth 2.0 / OIDC, mTLS between services, field-level encryption, HSM integration
ObservabilityOpenTelemetry traces, metrics and logs; Grafana dashboards included
DeploymentOn-premise, Azure, AWS, Google Cloud or EU sovereign cloud
ResilienceMulti-zone active-active, RPO 0, automated failover

Full API reference and sandbox access are available to prospective clients. Request access.

Talk to an architect.

Bring your current landscape and we will sketch a migration path with you in the first session.

Book a demoRead the architecture