Technical Deep Dive

Bucephalus Platform — Technical Architecture

Bucephalus is an event-driven, AI-augmented platform for detecting and preventing fraud and money laundering in banking. It is built for real-time decisioning, verifiable audit, regulatory alignment, and deployment inside the bank's own trust boundary — on-premise or in a private or sovereign regional cloud.

Real-time Event-driven Federated Auditable On-prem / private cloud
§ 1 — Principles

Architecture Principles

The six decisions the architecture is organised around. Every component below inherits these constraints.

01

Event-Driven

Every transaction, authentication, profile change and case action is an immutable event on the backbone. Components subscribe; they do not poll.

02

Real-Time Decisioning

Authorisation-path scoring completes within the issuer response budget. Batch is reserved for model training and retrospective analysis.

03

Modular Composition

Each capability is an independently deployable service with a versioned contract. Banks deploy only the modules they need.

04

Data Minimisation

Processing uses the smallest identifier set required for the decision. Raw PII stays inside the institution's trust boundary.

05

End-to-End Auditability

Every decision is reproducible from the original event plus the exact feature values and model version used to score it.

06

Deployment Sovereignty

Runs on-premise, in a bank's private cloud, or in a sovereign regional cloud. No dependency on a vendor-controlled tenant.

§ 2 — High-Level Architecture

Two Operational Planes

The platform splits cleanly along its latency budget. The real-time plane operates inside the authorisation response window; the compliance plane runs over longer horizons with richer context.

Bucephalus platform — two operational planes Real-time decisioning plane on top, compliance and investigation plane below. Integration layer and streaming backbone feed both planes; audit and data platform underpin everything. INGRESS Core Banking ISO 20022 / proprietary Card / Auth ISO 8583 Open Banking PSD2 XS2A Payments Rails SWIFT MT / MX Reference Data Sanctions · KYC · PEP Digital Channels Web · Mobile · Device STREAMING BACKBONE REAL-TIME DECISIONING PLANE inside the authorisation response window Decision Engine Rules + ML · Feature store Shadow evaluation Sanctions Screening Fuzzy + phonetic Continuous list refresh Fraud Scoring Device · Behavioural · Network Sub-100 ms p99 target Authorisation Response · Step-Up · Block · Review with full explainability payload COMPLIANCE & INVESTIGATION PLANE over hours, days, and months AML Monitoring Scenario · Behavioural Graph / network Case Management Workflow · SLA · 4-eyes Evidence chain Regulatory Reporting STR / SAR · supervisory machine-readable exports Federated Intelligence · Analytics · Threat Feeds anonymised typology exchange between institutions AUDIT · DATA PLATFORM

The integration layer normalises inbound events onto a single streaming backbone. The real-time plane consumes events inside the authorisation response window; the compliance plane consumes the same events over longer horizons with additional enrichment. Every decision and action is reflected into the audit and data platform on the right.

§ 3 — Components

Core Components

Eight services, each independently deployable, each sharing one audit-grade event log.

3.1

Integration Layer

Canonicalises heterogeneous banking events into a single domain model.

Adapters for ISO 20022, ISO 8583, SWIFT MT / MX, PSD2 XS2A, and proprietary core-banking protocols. Inbound events are validated, normalised, enriched with reference data, and emitted onto the backbone with stable correlation identifiers.

ISO 20022ISO 8583PSD2 XS2ASWIFT MT/MXOutbox pattern
3.2

Streaming Backbone

Durable, partitioned event log with replay and backpressure.

Log-structured, at-least-once delivery with per-key ordering (account and customer). Windowed joins, schema evolution via a registry, exactly-once semantics for sink writes. Sized for sustained millions of events per second at Tier-1 volumes.

Log-structuredAt-least-oncePer-key orderingSchema registry
3.3

Decision Engine

Hybrid rule + ML scoring on the authorisation path.

A declarative rule DSL runs alongside gradient-boosted and deep-learning models. A feature store supplies consistent online / offline features. Shadow evaluation lets new rules and models run silently in production before promotion. Target p99 inline latency is tens of milliseconds.

Rule DSLFeature storeShadow scoringChampion / challenger
3.4

AML Monitoring

Scenario-based, behavioural and graph-based detection.

Statistical baselining per customer segment, FATF-aligned typologies (structuring, layering, smurfing, trade-based ML), and graph analytics over the counter-party network to surface mule rings and layering chains. Outputs are cases, not raw alerts.

FATF typologiesBehavioural baseliningGraph analyticsPeer groups
3.5

Sanctions Screening

Real-time and batch list screening with linguistic matching.

Exact, fuzzy (Levenshtein, Jaro-Winkler), phonetic (Double Metaphone), and transliteration matching against EU consolidated, OFAC, UN, and national lists. Lists refresh continuously; every hit is explainable back to the rule and list version.

EU / OFAC / UN listsJaro-WinklerDouble MetaphoneList versioning
3.6

Case Management

Workflow, evidence and SLA control for investigators.

Configurable queues, four-eyes approvals, evidence attachment with chain-of-custody, SLA timers with escalation, integrated STR / SAR drafting, and bidirectional links to the originating events and decisions.

Four-eyesSLA timersChain-of-custodySTR / SAR export
3.7

Audit & Logging

Tamper-evident record of every decision and change.

Append-only, hash-chained log covering events, feature values, model versions, rule versions, analyst actions and configuration changes. WORM-compatible retention; reproducing any past decision requires only the audit store.

Append-onlyHash chainWORM retentionReproducible decisions
3.8

Data Platform

Operational, analytical and graph stores behind a unified access layer.

Low-latency operational store for live features, a columnar analytical store for investigation and reporting, and a graph store for network analysis. Tiered retention balances regulatory minima with cost; lineage is captured end-to-end.

OLTP + columnar + graphTiered retentionLineageUnified access
§ 3b — Data Flow

End-to-End Data Flow

The full picture: every inbound source, every processing lane, every feedback loop. The diagrams in this section are intentionally high-level — rule logic, model internals, tuning procedures, internal data models and specific optimisation techniques are not part of this public description.

flowchart LR
    A[Banking & external
source systems] --> B[Integration &
normalisation layer] B --> C[Event & data
backbone] C --> D[Real-time
decisioning] C --> E[Continuous AML
monitoring] C --> F[Sanctions &
watchlist screening] D --> G[Decision &
channel response] D --> H[Alert generation] E --> H F --> H H --> I[Case management &
investigation workbench] I --> J[Reporting &
regulatory export] D --> K[Audit &
logging layer] E --> K F --> K I --> K K --> J C --> L[Data platform
& analytics] L --> M[Model & pattern
refinement] M --> D M --> E N[Federated intelligence layer] --> M M --> N
§ 3c — Process Sequences

How the Platform Actually Runs

Four representative sequences, one per operational mode. Each is a view of the same underlying event-driven platform seen from a different time horizon and a different stakeholder.

Real-Time Payment Decisioning

Inside the authorisation response window — the channel is waiting on a synchronous answer.

sequenceDiagram
    autonumber
    participant CH as Channel / core system
    participant IG as Integration layer
    participant EB as Event & data backbone
    participant DE as Decision engine
    participant SS as Sanctions screening
    participant AM as AML / fraud scoring
    participant AL as Audit log
    participant CM as Case management

    CH->>IG: Transaction / event
    IG->>IG: Validation & normalisation
    IG->>EB: Structured event

    EB->>DE: Decision request
    DE->>SS: Fast screen
    SS-->>DE: Screening result

    DE->>AM: Risk & behavioural scoring
    AM-->>DE: Risk result

    DE->>DE: Aggregated decision logic
    DE->>AL: Decision + rationale metadata

    alt Approve
        DE-->>CH: Approved
    else Further review needed
        DE->>CM: Alert / case
        DE-->>CH: Step-up / review
    else Block
        DE->>CM: Critical alert / case
        DE-->>CH: Decline / block
    end
        

Continuous AML Monitoring & Investigation

Over the compliance horizon — hours to months — with the analyst workbench in the loop.

sequenceDiagram
    autonumber
    participant SRC as Source systems
    participant IG as Integration layer
    participant EB as Event & data backbone
    participant AML as AML monitoring
    participant SL as Sanctions / list check
    participant AG as Alert handling
    participant CASE as Case management
    participant AN as Analyst
    participant REP as Reporting
    participant AUD as Audit log

    SRC->>IG: Transaction & related events
    IG->>EB: Normalised events
    EB->>AML: Monitoring
    EB->>SL: List & match check

    AML-->>AG: AML risk signal
    SL-->>AG: Screening hit / match

    AG->>CASE: Create & prioritise case
    CASE->>AUD: Case-open log entry

    AN->>CASE: Open case
    CASE-->>AN: Events, history, related items
    AN->>CASE: Decision / note / next action
    CASE->>AUD: Analyst actions

    alt Reportable
        CASE->>REP: Generate regulatory report
        REP->>AUD: Export log entry
    else Internal closure
        CASE->>AUD: Closure log entry
    end
        

Federated Intelligence Exchange

How defensive capability travels between institutions while raw data stays at home.

sequenceDiagram
    autonumber
    participant B1 as Institution node A
    participant GOV as Sharing governance
    participant FP as Federated coordination
    participant B2 as Institution node B
    participant AUD as Audit log

    B1->>GOV: Prepare shareable pattern / aggregated signal
    GOV->>GOV: Check & filter
    GOV->>AUD: Sharing decision
    GOV->>FP: Approved, non-raw-data-shaped pattern
    FP->>B2: Pattern / regulatory intelligence
    B2->>AUD: Ingest & apply
        

Reporting & Auditability

What an internal auditor or an external supervisor actually sees when they pull a trail.

sequenceDiagram
    autonumber
    participant DET as Detection & decisioning layers
    participant CASE as Case management
    participant AUD as Audit & logging
    participant REP as Reporting module
    participant SUP as Internal / external reviewer

    DET->>AUD: Events & decision metadata
    CASE->>AUD: Analyst & workflow actions
    REP->>AUD: Report generation request
    AUD-->>REP: Traceable event chain
    REP-->>SUP: Auditable report / export
        

The diagrams above are deliberately kept at platform level. Internal rule logic, modelling methodology, tuning procedures, internal data models and specific optimisation techniques are not part of this public description.

§ 4 — Security

Security Posture

Bucephalus processes some of the bank's most sensitive data. The security model is zero-trust by default and assumes compromise at any single layer.

Zero-Trust Internal Fabric

Every service-to-service call is mutually authenticated with mTLS and short-lived SVID-style identities. No implicit network trust.

HSM-Backed Key Hierarchy

Root keys in FIPS 140-2 L3 HSMs, envelope encryption for data at rest, rotation and attestation as first-class operations.

Separation of Duties

Operators cannot read decision content; analysts cannot alter audit records; model promoters cannot approve their own releases.

Signed Build Artefacts

Container images, models and rule bundles are signed and verified at deploy time. SBOMs are emitted and retained per release.

Data Boundary Controls

PII processing, pseudonymisation and k-anonymisation happen before any cross-boundary transfer — including to the federation layer.

Secrets and Credentials

No long-lived credentials in services. Workload identity is issued dynamically and bound to the request context.

§ 5 — Federated Intelligence

Cooperation Without Data Sharing

Banks in the network improve each other's detection without raw data ever leaving any participant's trust boundary. The federation layer enforces a narrow, auditable contract for what is and is not allowed to cross institutional lines.

What leaves the bank

  • Anonymised typology signals and counter-party graph fragments above a k-anonymity threshold
  • Model gradient updates under differential-privacy noise, not model inputs or outputs
  • Hashed and salted identifiers for known-bad entity correlation
  • Aggregated performance metrics for central model evaluation

What never leaves the bank

  • Raw PII, account numbers, balances, or transaction amounts
  • Identifiable customer behaviour profiles
  • Case content, investigator notes, or SAR drafts
  • The bank's own proprietary rules and segmentations

Governance

  • Every cross-boundary transfer is logged into the bank's own audit store
  • Transfers are opt-in per data category and per counterparty
  • Participation can be paused or revoked without platform downtime
  • Contractual and regulatory conditions (GDPR Art. 6, banking secrecy) are encoded as policy, not only as paperwork
§ 6 — Observability & Operations

Operable in Production, Provable to Auditors

Observability is structured the same way a bank operations centre expects it.

Metrics
Golden signals per service (latency, traffic, errors, saturation) plus decision-quality metrics (FP rate, alert-to-case conversion).
Logs
Structured, correlation-id-tagged, shipped to the tenant's SIEM. No decision content leaves the bank's trust boundary by default.
Traces
OpenTelemetry end-to-end, including the model inference path. Every decision carries a trace id linking back to the raw event.
Runbooks
Every alert has a named owner, a severity ladder, and a runbook with first-response steps and rollback criteria.
§ 7 — Availability

High Availability & Continuity

The decisioning plane is on the critical path for customer payments. Its availability targets reflect that.

Deployment Topology
Active / active across two or more availability zones; multi-region is optional and depends on the bank's sovereignty stance.
Decisioning Continuity
Station-local scoring continues during a hub outage using the last validated model and rule bundle.
RPO
Effectively zero for the backbone; writes are durable before acknowledgement.
RTO
Minutes, not hours, for the decisioning plane; longer for analytical workloads by design.
Graceful Degradation
If downstream enrichment is unavailable, scoring falls back to a documented reduced feature set rather than failing open.
§ 8 — Regulatory Alignment

Designed Around EU Financial Regulation

The platform is aligned with the regulations that actually apply to the use case. The list below is indicative, not exhaustive, and evolves with the regulatory perimeter.

Instrument
Scope covered by the platform
AMLD6 / AMLR
Predicate offences, customer due diligence, suspicious activity reporting, record keeping.
PSD2 SCA & RTS
Strong customer authentication, transaction risk analysis exemptions, fraud reporting.
EBA Guidelines on ICT & Security Risk
ICT risk management, outsourcing, change management.
DORA
Operational resilience, incident classification and reporting, third-party risk.
EU AI Act
High-risk AI system obligations: risk management, data governance, logging, human oversight, transparency.
GDPR
Privacy by design (Art. 25), lawful basis, data subject rights, cross-border transfers.
NIS2
Cyber-risk management measures for essential entities, incident notification timelines.
§ 9 — Summary

An Architecture Built for How Banking Fraud Actually Works

Real-time where the attacker is fast, forensic where the regulator is patient, federated where cooperation helps, sovereign where data must stay. Bucephalus combines these properties into a single operational platform that a bank can run inside its own trust boundary.