🏗️ System Architecture

MudraHQ is engineered as a high-throughput, fault-tolerant financial operating system designed for Indian retail enterprises. It achieves sub-50ms API response times while operating on a strictly $0.00 / zero-charge cloud infrastructure model.

🌐 Cloud Infrastructure Topology

The production deployment combines Cloudflare Edge Anycast network with an Oracle Cloud Always Free Ampere A1 ARM64 virtual machine:

┌────────────────────────────────────────────────────────────────────────┐│                        MUDRAHQ DISTRIBUTED EDGE                        │└───────────────────────────────────┬────────────────────────────────────┘                                    │                                    ▼       ┌──────────────────────────────────────────────────────────┐       │   Cloudflare Anycast Global Edge (Universal SSL + WAF)   │       │   - mudrahq.tech (Primary React Native Mobile App)       │       │   - docs.mudrahq.tech (Heyo Documentation Site)          │       │   - Cloudflare Email Routing (support@mudrahq.tech)      │       └────────────────────────────┬─────────────────────────────┘                                    │                                    ▼       ┌──────────────────────────────────────────────────────────┐       │   Oracle Cloud Always Free VM (Ubuntu 24.04 LTS ARM64)   │       │   Ampere A1 (2 OCPUs, 12 GB RAM, 200 GB NVMe Storage)   │       ├──────────────────────────────────────────────────────────┤       │   • Nginx 1.24 (Reverse Proxy + Let's Encrypt SSL)       │       │   • PM2 Clustered API (2 Node.js v20.20.2 Workers)       │       │   • Docker Engine (PostgreSQL 15 Container on Port 5432) │       │   • Daily Encrypted SQLite/Postgres Backup Vault         │       └──────────────────────────────────────────────────────────┘

💻 Frontend Client Stack

MudraHQ features a universal codebase delivering both native mobile and desktop browser parity:

• Framework: React Native with Expo SDK 52.
• Web Engine: Compiled via @expo/webpack-config / metro into an optimized Single Page Application (SPA).
• UI & Aesthetics: React Native Paper Material Design 3, custom modern dark mode palettes, and Figtree/Inter typography.
• Vector Icons: @expo/vector-icons featuring over 2,000 Material Design, Ionicons, and Feather symbols.
• Thermal Paper Simulator: Canvas-based thermal paper receipts with authentic jagged-edge tearing simulation for retail counter validation.

⚡ Backend API Architecture

The backend REST API is built on high-concurrency Node.js microservices managed by PM2:

• Process Management: PM2 Cluster Mode utilizing 2 parallel worker processes on Ampere A1 ARM64 OCPUs with automatic zero-downtime reloads.
• Database & ORM: PostgreSQL 15 running in a tuned Docker container, mapped via Prisma ORM with declarative migrations and automated indexing.
• Rate Limiting: Sliding-window rate limiter preventing brute-force attacks on /api/auth/login (maximum 5 attempts per IP with exponential backoff).
• Security Middleware:
  • Strict 1MB JSON and URL-encoded payload limit.
  • OWASP Top 10 hardening (Helmet headers, strict CORS origin matching, XSS sanitization, SSRF protection).

🔒 Zero-Cost Infrastructure Guarantee

MudraHQ operates permanently under strict $0.00 infrastructure rules: