Architecture Overview

Service: Credit Engine
Language: Node.js/TypeScript
Responsibilities:
  - Credit score monitoring
  - Credit optimization algorithms
  - Dispute management
  - Credit simulation
 
Dependencies:
  - TigerBeetle (ledger)
  - Plaid (data source)
  - Supabase (metadata)
  - Redis (caching)
 
APIs:
  - /api/credit/score - Get credit scores
  - /api/credit/optimize - Optimization recommendations
  - /api/credit/simulate - What-if analysis
  - /api/credit/dispute - Dispute management

Service: Payment Service
Language: Node.js/TypeScript
Responsibilities:
  - Payment processing
  - Bill payments
  - Subscription management
  - Transfer operations
 
Dependencies:
  - Hyperswitch (payment orchestration)
  - TigerBeetle (ledger recording)
  - Redis (idempotency)
 
APIs:
  - /api/payments/* - Payment operations
  - /api/transfers/* - Money transfers
  - /api/bills/* - Bill payments
  - /api/subscriptions/* - Recurring payments

Service: Analytics Service
Language: Python/TypeScript
Responsibilities:
  - Data aggregation
  - ML model serving
  - Report generation
  - Real-time analytics
 
Dependencies:
  - ClickHouse (analytics DB)
  - TensorFlow/PyTorch (ML)
  - Apache Kafka (streaming)
 
APIs:
  - /api/analytics/* - Analytics queries
  - /api/insights/* - AI insights
  - /api/reports/* - Report generation

Service: AI Service
Language: Python
Responsibilities:
  - Natural language processing
  - Predictive modeling
  - Recommendation engine
  - Anomaly detection
 
Dependencies:
  - OpenAI/Anthropic APIs
  - Custom ML models
  - Vector database (Pinecone)
 
APIs:
  - /api/ai/chat - Conversational AI
  - /api/ai/predict - Predictions
  - /api/ai/recommend - Recommendations

// Event Schema
interface FinancialEvent {
  id: string
  type: 'transaction' | 'balance_update' | 'credit_change'
  timestamp: Date
  userId: string
  accountId: string
  data: Record<string, any>
  metadata: {
    source: string
    version: string
    correlation_id: string
  }
}
 
// Event Processing
class EventProcessor {
  async processEvent(event: FinancialEvent) {
    // Record in ledger
    await this.recordInLedger(event)
 
    // Update cache
    await this.updateCache(event)
 
    // Trigger analytics
    await this.triggerAnalytics(event)
 
    // Send notifications
    await this.notifySubscribers(event)
  }
}

// Authentication Flow
class AuthenticationService {
  async authenticate(request: AuthRequest): Promise<AuthResult> {
    // 1. Verify JWT token
    const token = await this.verifyJWT(request.token)
 
    // 2. Check session validity
    const session = await this.validateSession(token.sessionId)
 
    // 3. Verify MFA if required
    if (this.requiresMFA(request.resource)) {
      await this.verifyMFA(request.mfaCode)
    }
 
    // 4. Check permissions
    const permissions = await this.checkPermissions(
      token.userId,
      request.resource,
      request.action
    )
 
    // 5. Rate limit check
    await this.checkRateLimit(token.userId, request.resource)
 
    return {
      authorized: true,
      permissions,
      sessionId: session.id
    }
  }
}

Service Communication:
  - mTLS between all services
  - Service identity verification
  - Encrypted service-to-service communication
  - Policy-based access control
 
Implementation:
  - Istio service mesh
  - Automatic certificate rotation
  - Traffic encryption
  - Observability and tracing

Monitoring Stack:
  SIEM:
    - Centralized logging (ELK stack)
    - Real-time threat detection
    - Anomaly detection
    - Compliance reporting
 
  Threat Detection:
    - Failed authentication attempts
    - Unusual transaction patterns
    - API abuse detection
    - Data exfiltration attempts
 
  Incident Response:
    - Automated alerting
    - Playbook execution
    - Evidence collection
    - Post-mortem analysis

Production Cluster:
  Control Plane:
    - 3 master nodes (HA configuration)
    - etcd cluster (distributed state)
    - API server with HA proxy
 
  Worker Nodes:
    - 10 nodes minimum (auto-scaling 10-50)
    - Node specifications:
      - 16 vCPUs
      - 64GB RAM
      - 500GB SSD
 
  Namespaces:
    - production (main services)
    - financial-core (TigerBeetle, Hyperswitch)
    - monitoring (Prometheus, Grafana)
    - ingress (API Gateway)

Service Resources:
  Credit Engine:
    replicas: 3-10 (HPA)
    cpu: 2000m request, 4000m limit
    memory: 4Gi request, 8Gi limit
 
  Payment Service:
    replicas: 3-10 (HPA)
    cpu: 2000m request, 4000m limit
    memory: 4Gi request, 8Gi limit
 
  Analytics Service:
    replicas: 2-5 (HPA)
    cpu: 4000m request, 8000m limit
    memory: 8Gi request, 16Gi limit
 
  AI Service:
    replicas: 2-5 (HPA)
    cpu: 4000m request, 8000m limit
    memory: 8Gi request, 16Gi limit
    gpu: 1 (for ML inference)

Region: US-East-1 (Primary)
├── AZ-1
│   ├── K8s Master
│   ├── Worker Nodes
│   └── TigerBeetle Node
├── AZ-2
│   ├── K8s Master
│   ├── Worker Nodes
│   └── TigerBeetle Node
└── AZ-3
    ├── K8s Master
    ├── Worker Nodes
    └── TigerBeetle Node

Region: US-West-2 (DR)
├── Standby cluster
├── Replicated data
└── Ready for failover

Metrics Collection:
  Prometheus:
    - Service metrics
    - Custom business metrics
    - Infrastructure metrics
    - Alert rules
 
  Grafana Dashboards:
    - Service health
    - Business KPIs
    - Infrastructure status
    - Cost monitoring
 
Logging Architecture:
  Fluentd:
    - Log collection
    - Log parsing
    - Log forwarding
 
  Elasticsearch:
    - Log storage
    - Full-text search
    - Log retention (30 days)
 
  Kibana:
    - Log visualization
    - Dashboard creation
    - Alert configuration
 
Tracing:
  Jaeger:
    - Distributed tracing
    - Latency analysis
    - Dependency mapping
    - Performance bottlenecks