We use cookies and similar technologies to improve your experience, analyze site traffic, and personalize content. By clicking "Accept", you consent to our use of cookies for analytics and performance tracking.

Cookie Consent

See FERNEL in action. We will walk you through the architecture, show real integration flows, and answer your technical questions.

Request a Demo

Questions about partnerships, press, or anything else? Reach out directly.

General Inquiries

Get in Touch

The page you are looking for does not exist or has been moved.

Page Not Found

An unexpected error occurred. Please try again later.

Something Went Wrong

Three strictly isolated layers. Zero opaque runtime behavior. By minimizing the dependency surface, Fernel guarantees predictable, audit-ready financial operations that survive regulatory scrutiny.

Zero-Loss Orchestration for mission-critical payments

Durable Workflow Engine

The Brain

High-Performance Management

The Face

Safety-Critical Engineering with zero external dependencies

Immutable Ledger Core

The Rock

"Coreless"

Advantage

Evaluate the architecture, review the documentation, and talk to our team about your requirements.

Ship Financial Products

on a Solid Foundation.

Integration requires predictability. Fernel exposes its internal architecture through strict REST APIs, type-safe SDKs, and exhaustive documentation designed for senior engineers.

OpenAPI-first design with a type-safe client SDK for predictable integration. Additional SDKs planned.

REST API & Client SDK

ADRs, API references, integration guides. Everything your team needs to evaluate and ship.

Exhaustive Documentation

No black box. Your compliance team can review the architecture and verify security practices before signing.

Fully Auditable

reliability

Built for developers who care about

We've received your inquiry and will get back to you shortly at {email}. Our team typically responds within 24 hours.

Thank You!

Talk to our team about your requirements. No sales pitch, real conversation.

Engineered for absolute state integrity. Wallets, payments, and compliance infrastructure that refuse to drift.

Every entry traceable, every balance reconstructable at any point in time.

Audit-friendly by design

High-throughput processing with predictable latency.

Immutable double-entry

Workflows ensure payments complete or roll back cleanly.

Durable workflows

Create multi-currency wallets with dedicated account identifiers.

Multi-currency accounts

build financial products

Core primitives for

No partial states. No silently swallowed exceptions. Fernel provides safety-critical infrastructure enforcing strict serializability across ledgers, durable payment workflows, and compliance primitives.

Financial State is Absolute.

The Financial Operating System

Fernel

Regulators audit architecture, not marketing. Fernel embeds compliance into the infrastructure layer, minimizing operational risk through immutable data structures.

Immutable audit trails, double-entry integrity, and tenant isolation. The building blocks auditors look for.

Compliance-Ready Architecture

Architectural foundations for ICT risk management (Art. 5-15): deterministic execution, hash-chained audit, minimal dependency surface.

DORA-Aligned Architecture

Consistent latency under load. No unpredictable pauses, no hidden overhead, no surprises.

Predictable Performance

Self-contained deployment. Minimal external dependencies. Verifiable builds.

Minimal Attack Surface

Regulatory Alignment

Safety-Critical

Built for

Finance

Wallets, payments, compliance, reconciliation. One consistent REST API covering the full financial operations lifecycle.

Our team has built financial systems across banking, payments, and compliance since 2010.

Core banking systems hide their flaws behind vendor lock-in. Fernel inverts this model. We provide a transparent, verifiable financial core built on absolute technical honesty. You own the architecture.

The modern financial core. Redefined.

Why Fernel

Zero-entry and single-entry shortcuts fail under regulatory scrutiny. How double-entry invariants enforced at the engine level prevent ledger drift.

Why Double-Entry is Non-Negotiable for Modern Financial Infrastructure

DORA is not a compliance checkbox. It is a systems specification with architectural implications for determinism, traceability, and resilience.

DORA for Infrastructure Providers: What It Actually Requires

Three layers, three failure domains. How the separation of ledger engine, orchestration, and domain logic creates a system that regulators can audit.

Anatomy of a Financial Operating System

Why native semantic classification (Domain/Family/SubFamily) matters more than XML parsing for automated reconciliation and scheme-agnostic architecture.

ISO 20022 Beyond Format Conversion

Lock contention, GC pauses, and deserialization overhead. What a purpose-built settlement engine does differently.

Deterministic Settlement: Why General-Purpose Databases Fail at Scale

Saga compensations are necessary but insufficient. Durable execution provides exactly-once guarantees that financial processes require.

Durable Execution vs. the Saga Pattern for Payment Workflows

Four layers of tenant isolation from API gateway to database. Defense in depth for financial infrastructure.

Multi-Tenant Isolation: Why Row-Level Security is Not Enough

Reject, Return, Refund, Reversal. Four distinct lifecycle events, each with different ledger impact, PSD2 timelines, and ISO reason codes.

SEPA R-Transactions: A Technical Reference

Amdahl's Law and the limits of general-purpose databases for high-throughput settlement workloads. The case for purpose-built engines.

Why General-Purpose Databases Are the Wrong Foundation for Financial OLTP

Jurisdiction-aware CDD policies, provider abstraction, and risk-level-driven verification depth. Configuration over code.

Automating Customer Due Diligence Without Hard-Coding Compliance

Confidence-scored matching, ISO 20022 transaction classification, and the operational impact of daily automated reconciliation.

From Monthly Reconciliation to Continuous Matching

Segregating client funds is a regulatory requirement, not a feature. Account categories, transfer rules, and reporting obligations.

TSE-certified for KassenSichV