Skip to content

ARCHITECTURE.md

Latest commit

 

History

History
280 lines (224 loc) · 14.3 KB

ARCHITECTURE.md

File metadata and controls

280 lines (224 loc) · 14.3 KB
Raw

Architecture Overview

NexaFi's technical architecture, design patterns, and system components.

Table of Contents

  1. System Overview
  2. Microservices Architecture
  3. Data Flow
  4. Technology Stack
  5. Deployment Architecture

System Overview

NexaFi implements a cloud-native microservices architecture using Domain-Driven Design (DDD) principles.

High-Level Architecture

┌─────────────────────────────────────────────────────────────────────┐
│                         Client Applications                          │
│  ┌──────────────┐  ┌──────────────┐  ┌────────────────────────┐   │
│  │ Web Dashboard│  │  Mobile App  │  │  Third-Party Clients   │   │
│  │  (React)     │  │  (Flutter)   │  │  (REST/GraphQL API)    │   │
│  └──────────────┘  └──────────────┘  └────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────┘
                                  │
                                  ▼
┌─────────────────────────────────────────────────────────────────────┐
│                           API Gateway (Port 5000)                    │
│  ┌────────────────────────────────────────────────────────────┐    │
│  │  Rate Limiting │ Auth │ Circuit Breaker │ Load Balancing   │    │
│  └────────────────────────────────────────────────────────────┘    │
└─────────────────────────────────────────────────────────────────────┘
                                  │
                    ┌─────────────┴─────────────┐
                    ▼                           ▼
┌────────────────────────────┐    ┌────────────────────────────┐
│    Core Domain Services    │    │  Supporting Services       │
├────────────────────────────┤    ├────────────────────────────┤
│ • User Service (5001)      │    │ • Compliance Service (5005)│
│ • Ledger Service (5002)    │    │ • Notification Svc (5006)  │
│ • Payment Service (5003)   │    │ • Analytics Service (5007) │
│ • AI Service (5004)        │    │ • Document Service (5009)  │
│ • Credit Service (5008)    │    │ • Open Banking GW (5010)   │
│ • Auth Service (5011)      │    │ • Enterprise Integrations  │
└────────────────────────────┘    └────────────────────────────┘
                    │                           │
                    └─────────────┬─────────────┘
                                  ▼
┌─────────────────────────────────────────────────────────────────────┐
│                         Data Layer                                   │
│  ┌──────────────┐  ┌──────────────┐  ┌────────────────────────┐   │
│  │  PostgreSQL  │  │    Redis     │  │  Elasticsearch         │   │
│  │  (Primary)   │  │   (Cache)    │  │  (Search & Analytics)  │   │
│  └──────────────┘  └──────────────┘  └────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────┘

Microservices Architecture

Service Catalog

Service Port Language Purpose Dependencies
API Gateway 5000 Python/Flask Entry point, routing, security All services
User Service 5001 Python/Flask User management PostgreSQL, Redis
Ledger Service 5002 Python/Flask Accounting, multi-currency PostgreSQL
Payment Service 5003 Python/Flask Payment processing PostgreSQL, Redis
AI Service 5004 Python/FastAPI ML predictions PyTorch, Redis
Compliance Service 5005 Python/Flask AML/KYC PostgreSQL
Notification Service 5006 Python/Flask Multi-channel notifications SMTP, SMS providers
Analytics Service 5007 Python/Flask Business intelligence PostgreSQL, Elasticsearch
Credit Service 5008 Python/FastAPI Credit scoring PostgreSQL, ML models
Document Service 5009 Python/Flask Document processing S3, OCR APIs
Open Banking GW 5010 Python/Flask Bank integrations External bank APIs
Auth Service 5011 Python/Flask Authentication, OAuth 2.1 PostgreSQL, Redis

Service Communication

  • Synchronous: REST API (HTTP/JSON)
  • Asynchronous: Planned (Kafka/RabbitMQ)
  • Service Discovery: Static configuration (moving to Consul)

Module Mapping

backend/
├── api-gateway/                 → API Gateway & routing
│   └── src/main.py             → Entry point
├── user-service/                → User management
│   └── src/main.py             → User APIs
├── auth-service/                → Authentication
│   └── src/main.py             → OAuth 2.1, JWT
├── ledger-service/              → Financial ledger
│   └── src/main.py             → Accounting APIs
├── payment-service/             → Payments
│   └── src/main.py             → Transaction processing
├── ai-service/                  → ML predictions
│   └── src/main.py             → AI models & inference
├── compliance-service/          → AML/KYC
│   └── src/main.py             → Compliance checks
├── notification-service/        → Notifications
│   └── src/main.py             → Email, SMS, push
├── analytics-service/           → Analytics
│   └── src/main.py             → Reporting & BI
├── credit-service/              → Credit scoring
│   └── src/main.py             → Risk assessment
├── document-service/            → Document processing
│   └── src/main.py             → OCR, storage
├── open-banking-gateway/        → Bank integrations
│   └── src/main.py             → PSD2 APIs
└── shared/                      → Shared libraries
    ├── middleware/              → Auth, rate limiting
    ├── validators/              → Input validation
    ├── database/                → DB management
    ├── nexafi_logging/          → Structured logging
    ├── audit/                   → Audit logging
    └── security/                → Encryption, hashing

Data Flow

Transaction Flow Example

User → Web Dashboard → API Gateway → Payment Service → Ledger Service
                            ↓              ↓                  ↓
                        Auth Check     Process Payment    Record Entry
                            ↓              ↓                  ↓
                        User Service   Fraud Check       PostgreSQL
                            ↓              ↓
                        PostgreSQL     AI Service
                                           ↓
                                      ML Model

Authentication Flow

1. User submits credentials → API Gateway
2. API Gateway → Auth Service
3. Auth Service validates → Database
4. Auth Service generates JWT → Returns to Gateway
5. Gateway returns JWT → User
6. User includes JWT in subsequent requests
7. Gateway validates JWT → Routes to services

Technology Stack

Backend

Layer Technology Purpose
Languages Python 3.11+, Node.js 18+ Primary development
Frameworks Flask, FastAPI, NestJS Web frameworks
Databases PostgreSQL 15+, MongoDB Data storage
Caching Redis 7+ Performance, sessions
Search Elasticsearch 8+ Full-text search
Messaging Planned: Kafka, RabbitMQ Async communication

Frontend

Component Technology Purpose
Web React 18+, Next.js, TypeScript Web dashboard
Mobile Flutter 3.0+ iOS/Android app
State Redux Toolkit State management
Styling Tailwind CSS UI styling
Charts D3.js, Recharts Data visualization

ML/AI

Component Technology Purpose
Frameworks PyTorch 2.0+, TensorFlow Deep learning
NLP Hugging Face Transformers Text processing
MLOps MLflow, Kubeflow Model lifecycle
Feature Store Feast Feature management
Inference NVIDIA Triton Model serving

Infrastructure

Component Technology Purpose
Containers Docker Containerization
Orchestration Kubernetes, Helm Container orchestration
Service Mesh Istio Service communication
CI/CD GitHub Actions, ArgoCD Automation
IaC Terraform Infrastructure as code
Monitoring Prometheus, Grafana Observability
Logging ELK Stack Log aggregation
Tracing Jaeger, OpenTelemetry Distributed tracing

Deployment Architecture

Environment Strategy

Environment Purpose Infrastructure
Development Local development Docker Compose
Staging Pre-production testing Kubernetes (single cluster)
Production Live system Kubernetes (multi-region)

Cloud Providers

  • Primary: AWS (EKS, RDS, S3, Lambda)
  • Secondary: GCP (GKE, Cloud SQL, BigQuery)
  • Multi-cloud for resilience

High Availability

  • Load Balancing: Application Load Balancer
  • Auto-scaling: Horizontal Pod Autoscaler
  • Failover: Active-active multi-region
  • Backup: Automated daily backups, 30-day retention

Design Patterns

Pattern Usage Location
Circuit Breaker Fault tolerance API Gateway
Retry Pattern Resilience All services
CQRS Planned Analytics Service
Event Sourcing Planned Audit logging
Saga Pattern Planned Distributed transactions
API Gateway Routing, security API Gateway
Repository Pattern Data access All services
Factory Pattern Object creation Shared libraries

Security Architecture

Security Layers

  1. Network Security: VPC, security groups, WAF
  2. Application Security: Input validation, CSRF protection
  3. Data Security: Encryption at rest and in transit
  4. Identity Security: OAuth 2.1, MFA, RBAC
  5. Monitoring: SIEM, intrusion detection

Authentication & Authorization

  • Authentication: JWT with refresh tokens
  • Authorization: RBAC with fine-grained permissions
  • Session Management: Redis-backed sessions
  • API Keys: For third-party integrations

Performance Considerations

Caching Strategy

  • L1 Cache: In-memory (per service)
  • L2 Cache: Redis (shared)
  • CDN: CloudFront for static assets

Database Optimization

  • Indexing: Strategic indexes on high-query columns
  • Connection Pooling: Configured per service
  • Read Replicas: For analytics workloads
  • Partitioning: Time-series data