Case Study: Open Banking

Case Study: Open Banking Implementation for a UAE Bank (PSD2 + FAPI Compliant)

(Enterprise Architecture, Solution Design, and Deployment)

🏦 1. Business Context

Client: Leading Tier-1 UAE Retail BankObjective: Comply with UAE Open Banking & Open Finance framework mandated by the Central Bank of UAE (CBUAE) and enable secure, consent-driven data sharing with fintechs and partners.Goal:

• Build a PSD2-compliant Open Banking platform

• Support Account Information Services (AIS) and Payment Initiation Services (PIS)

• Enable partner onboarding, API monetization, and FAPI-compliant consent flow

• Improve developer experience and ecosystem participation

🎯 2. Business Drivers & Key Outcomes

Business Objective	Expected Outcome
Regulatory compliance (PSD2/FAPI/CBUAE)	Achieve certification by regulatory sandbox
Customer control & trust	Transparent, consent-based data access
API-driven innovation	New digital partnerships (Fintechs, Aggregators)
Reduced time-to-market	Developer portal, sandbox, and onboarding automation
Secure data sharing	End-to-end encryption, FAPI-based consent, OAuth2

🧱 3. Architecture Overview

🔹 High-Level Architecture Layers

Layer	Key Components	Description
Channel Layer	Partner Apps, Fintech Portals, Developer Portal	External third parties consuming APIs
API Management Layer	API Gateway, Developer Portal, Analytics	API exposure, throttling, key management
Security & Consent Layer	OAuth2, OpenID Connect, FAPI, Consent Store	Token issuance, consent capture & validation
Integration Layer	ESB / iPaaS (MuleSoft / Apigee / Azure Integration Service)	Routing, transformation, orchestration
Core Banking Systems	CASA, Loans, Cards, Payments	System of record for customer data
Data Layer	Customer 360, Audit Logs, API Usage Analytics	Data lineage, observability
Infrastructure Layer	Azure Cloud (AKS, Key Vault, Azure SQL, Monitor)	Cloud-native, scalable deployment

🔐 4. Security & Compliance Architecture

Security Standard	Purpose
OAuth 2.0	Access control & token issuance
OpenID Connect (OIDC)	Customer identity & authentication
FAPI (Financial-grade API)	Enhanced security & customer consent integrity
MTLS (Mutual TLS)	Bank–Partner trust verification
JWS/JWE	Message signing & encryption
Consent API	Stores, validates, and revokes user consent
Audit Trail	Immutable consent & transaction logging

🧩 Consent Management Flow

Customer → Fintech App → Bank Authorization Server
→ Customer Login (OIDC) → Consent Page (Read Accounts, Initiate Payments)
→ Consent Artefact Signed → Access Token Issued → API Access Granted

Each consent artefact is stored with:

• Scope (Data types shared)

• Validity (Duration)

• Purpose (Usage)

• Audit Trail (Regulatory compliance)

⚙️ 5. Solution Design

🔸 Step-by-Step Solution Implementation

Phase 1: Foundation

• Set up API Gateway (Azure API Management / Apigee)

• Configure OAuth2 Authorization Server and FAPI compliance layer

• Deploy Developer Portal for third-party onboarding and API testing

• Establish sandbox environment

Phase 2: Core Enablement

• Integrate with Core Banking systems through service adapters (REST/SOAP)

• Define Open APIs per PSD2 (Accounts, Transactions, Payments)

• Implement Consent Service (customer consent capture, revoke, audit)

• Integrate with Customer Authentication Service (OIDC)

Phase 3: Security & Compliance

• Enable Mutual TLS (MTLS) between bank and partners

• Apply JWS/JWE for signing and encryption of payloads

• Integrate SIEM and Audit Logging for regulatory traceability

Phase 4: Partner & Ecosystem Enablement

• Onboard partners via Developer Portal

• Expose API Catalogs and mock endpoints (sandbox)

• Enable API analytics and usage-based monetization model

Phase 5: Production Rollout

• Conduct CBUAE compliance testing & certification

• Migrate to active-active deployment on Azure AKS

• Implement blue-green deployments for zero downtime releases

• Enable real-time monitoring with Prometheus & Grafana

☁️ 6. Deployment Architecture (Azure Example)

Services Used:

• Azure API Management – External API Gateway

• Azure AKS (Kubernetes) – Microservices hosting

• Azure AD / B2C – OAuth2 + OIDC identity layer

• Azure Key Vault – Key & certificate management

• Azure SQL / Cosmos DB – Transaction and consent store

• Azure Front Door + WAF – Global load balancing + Security

• Azure Monitor + Log Analytics – Observability & auditing

🧠 7. Governance & Risk Mitigation

Risk	Mitigation
Partner misuse of data	FAPI-compliant consent validation
API throttling or abuse	Quota limits & API Gateway policies
Regulatory non-compliance	Continuous audit & CBUAE sandbox certification
Identity spoofing	Mutual TLS & certificate pinning
Data privacy violation	End-to-end encryption + consent expiry enforcement

📊 8. KPIs & Success Metrics

KPI	Target
Partner onboarding time	< 3 days
API availability	99.9%
Consent approval latency	< 1 sec
Average response time (API)	< 300ms
Customer complaints related to data misuse	Zero
Time-to-market for new APIs	< 4 weeks

🧩 9. Outcome & Benefits

✅ Regulatory Compliance: Achieved PSD2/FAPI certification from CBUAE✅ Partner Ecosystem: 30+ fintech partners integrated within 6 months✅ Customer Empowerment: Transparent, secure consent experience✅ Operational Efficiency: Reduced partner onboarding time by 70%✅ Cloud Scalability: Auto-scaled APIs to 500K+ requests/day

🏁 10. Architecture Summary (Text Visualization)

[Fintech Apps]
   │
   ▼
[API Gateway - Azure API Mgmt]
   │  (OAuth2 + MTLS + Rate Limit)
   ▼
[Consent Service + Auth Server]
   │
   ▼
[Integration Layer / ESB]
   │
   ▼
[Core Banking APIs / Customer 360 / Payments Engine]
   │
   ▼
[Audit + Analytics + Logging]