Azure Services -Digital Lending

Absolutely — I’ll break down each Azure service used in the Digital Lending Modernization architecture and explain:

• Role in architecture

• Step-by-step configuration/implementation

• Integration with microservices

• Compliance/security controls

• Best practices for BFSI active-active setup

This will give you an end-to-end view and you can map it directly into design and implementation phases.

Azure Services – Step-by-Step Implementation

1. Azure Front Door (Global Routing + WAF)

Role

• Global entry point for Angular SPA and API traffic.

• Provides WAF (Web Application Firewall) to mitigate DDoS, OWASP attacks.

• Routes requests to nearest active region (active-active deployment).

Step-by-Step

1. Create Front Door in Azure Portal.

2. Configure two backends:

   • APIM in Central India

   • APIM in South India

3. Enable health probes for failover.

4. Attach WAF policy (block SQLi, XSS, rate limiting).

5. Configure custom domain + HTTPS (TLS) with Azure-managed certificates.

Integration

• Angular SPA → Front Door → APIM (private AKS API).

Compliance

• WAF logs → Azure Monitor → stored in Data Lake (7 years for audit).

• Geo-filtering → restrict access to India (RBI compliance).

2. Azure API Management (APIM)

Role

• API gateway for microservices.

• Enforces throttling, JWT auth, and multi-tenant routing.

Step-by-Step

1. Deploy APIM in internal VNet mode (integrated with AKS private subnet).

2. Define APIs:

   • Loan API (/loan)

   • KYC API (/kyc)

   • Credit API (/credit)

3. Apply policies:

   • Rate limit per tenant (ICICI vs HDFC).

   • Transform headers (add tenantId).

   • Mask sensitive PII in logs.

Integration

• Exposes APIs securely to Angular app (public subnet).

• Routes to Istio ingress gateway in AKS.

Compliance

• APIM audit logs → Azure Monitor → WORM-enabled Data Lake.

• Enforce OAuth2/JWT from Azure AD B2C.

3. Azure Kubernetes Service (AKS) + Istio

Role

• Host microservices (Loan, KYC, Credit, Fraud, Disbursement).

• Istio provides service mesh: mTLS, traffic routing, circuit breaking.

Step-by-Step

1. Provision AKS with private cluster mode.

2. Install Istio via Helm:

   bash

   CopyEdit

   helm repo add istio https://istio-release.storage.googleapis.com/charts helm install istio-base istio/base -n istio-system helm install istiod istio/istiod -n istio-system

3. Configure Istio Ingress Gateway for API traffic.

4. Define DestinationRules and VirtualServices for canary deployments.

5. Enable pod auto-scaling with KEDA (event-driven).

Integration

• All microservices communicate over Istio with mTLS.

• Kafka (Event Hub) also integrated into Istio mesh for observability.

Compliance

• AKS nodes in India region; Azure Policy denies other region deployments.

• Secrets via Key Vault CSI driver.

4. Azure Event Hub (Kafka API)

Role

• Event store for event sourcing pattern.

• Used by CQRS: Loan events → Projections in Cosmos DB/Azure SQL.

Step-by-Step

1. Create Event Hub namespace with Kafka endpoint enabled.

2. Create topic loan-events with partitions (key = loanId).

3. Configure retention = 7 days (hot), archive to Data Lake for long-term.

4. Spring Boot microservices use Kafka clients to publish/consume.

Integration

• Loan Service emits LoanApplied.

• KYC/Credit/Fraud services consume & emit KYCVerified, CreditChecked, etc.

Compliance

• Immutable event log replicated to Data Lake (WORM for 10 years).

• Encryption with Azure-managed keys.

5. Azure Cosmos DB

Role

• NoSQL database for projections (read side of CQRS).

• Stores KYC documents and real-time loan status views.

Step-by-Step

1. Create Cosmos DB (API: Core SQL).

2. Define container loanStatusView partitioned by loanId.

3. Set TTL for projections (e.g., 90 days) if ephemeral.

4. Enable multi-region writes (for active-active).

Integration

• Azure Functions consume Event Hub → update Cosmos projections.

• Angular dashboard queries Cosmos read models via APIM.

Compliance

• Data encrypted with CMK (Key Vault).

• Tenant isolation via partition key.

6. Azure SQL Database

Role

• Relational data store for loan master records.

• Used for financial transactions, regulatory reports.

Step-by-Step

1. Create Azure SQL in business-critical tier (HA + geo-replication).

2. Configure failover groups between regions.

3. Implement stored procs for reconciliation with legacy core banking.

Integration

• Disbursement service writes final loan transactions.

• Synapse pulls data for RBI/SEBI reports.

Compliance

• TDE (Transparent Data Encryption) mandatory.

• Row-level security for tenant isolation.

7. Azure Data Lake Storage (WORM)

Role

• Immutable storage for audit trails (RBI requires 10-year retention).

Step-by-Step

1. Create Data Lake Gen2 with WORM (immutability) enabled.

2. Configure Event Hub capture to write raw events to Data Lake.

3. Partition data by YYYY/MM/DD for efficient query.

Integration

• Synapse Analytics queries directly for compliance dashboards.

Compliance

• WORM policy locked (cannot delete/modify).

• Access via RBAC and Managed Identities.

8. Azure Synapse Analytics + Power BI

Role

• Analytics for KPIs (loan turnaround, fraud detection rate, NPA trends).

• Generates SEBI/RBI regulatory reports.

Step-by-Step

1. Create Synapse workspace connected to Data Lake and Azure SQL.

2. Build pipelines for:

   • Daily loan disbursement report

   • Monthly regulatory compliance metrics

3. Power BI dashboards connected to Synapse views.

9. Azure DevOps + DevSecOps Pipeline

Role

• CI/CD with integrated security (DevSecOps).

Step-by-Step

1. Code repository (GitHub or Azure Repos).

2. CI pipeline:

   • Build → Unit Test → SonarQube (SAST) → Dependency Scan (OWASP) → Docker Build → ACR.

3. CD pipeline:

   • Helm deploy to AKS (canary via Istio).

   • DAST (OWASP ZAP) on staging.

4. Post-deployment:

   • Azure Policy compliance check.

   • Monitor via Azure Monitor.

10. Azure Policy & Blueprints

Role

• Enforce governance:

  • Region restriction (India only).

  • Encryption at rest.

  • Only ACR images deployable to AKS.

Step-by-Step

1. Create custom policy definitions (deny non-India region).

2. Assign policies at subscription level.

3. Bundle into Blueprint:

   • VNet

   • AKS

   • APIM

   • Key Vault

   • Event Hub

11. Azure Virtual Network (VNet) with Public/Private Subnets

Role

• Network isolation for BFSI workloads.

Step-by-Step

1. Create VNet with two subnets:

   • Public Subnet: Angular app, Front Door, APIM.

   • Private Subnet: AKS, Event Hub, Cosmos DB, Azure SQL.

2. NSG Rules:

   • Public subnet → Private subnet (API only).

   • Private subnet → Internet (egress via NAT Gateway).

   • Deny lateral movement between private resources.

12. Azure Key Vault

Role

• Centralized secret management for microservices.

Step-by-Step

1. Create Key Vault with RBAC enabled.

2. Store:

   • DB connection strings

   • API keys (Credit Bureau, Aadhaar API)

   • Certificates

3. Integrate with AKS using Key Vault CSI driver.

Compliance Considerations (Across All Services)

• Data Residency: All services deployed in India Central/South.

• Encryption: TDE for SQL, encryption-at-rest for Cosmos/Blob, Key Vault for keys.

• Audit Logging: Azure Monitor → Data Lake.

• Network Security: Private Endpoints, NSG, no public DB exposure.

KPIs Tracked via Synapse/Power BI

Business KPIs

• Loan approval SLA (minutes)

• Drop-off rate during KYC

• Fraud detection accuracy

• NPA ratio

Operational KPIs

• API latency (P95)

• Event Hub lag

• AKS node utilization

• Deployment success rate