Code Review Platform — Cloud-Native DevOps Case Study

Live Demo: https://codereviewer-4ph0.onrender.com/

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0. Overview

A production-style, containerized code review SaaS showcasing modern DevOps practices: microservices, reverse proxy routing, CI/CD readiness, and scalable deployment patterns.

This project demonstrates how a full-stack system is structured for deployment, scaling, and observability in real-world environments.

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1. Architecture

1.1 High-Level System Design

                   ┌────────────────────────────┐
                   │   Nginx Reverse Proxy      │
                   │   (Edge Gateway :8800)     │
                   └─────────────┬──────────────┘
                                 │
         ┌───────────────────────┴───────────────────────┐
         │                                               │
┌────────▼────────┐                           ┌──────────▼─────────┐
│ Frontend        │                           │ Backend API        │
│ React + Vite    │                           │ Node.js + Express  │
│ Served via Nginx│                           │ Port 3000          │
└────────┬────────┘                           └──────────┬─────────┘
         │                                               │
         └───────────────────┬───────────────────────────┘
                             │
                    ┌────────▼────────┐
                    │ External APIs   │
                    │ (OpenAI)        │
                    └─────────────────┘

1.2 Design Principles

• Stateless frontend and backend services
• Isolated containers per service
• Internal Docker DNS-based service discovery
• Reverse proxy as single entry point
• Horizontal scaling-ready architecture

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2. Infrastructure (Docker-Based)

2.1 Docker Compose Orchestration

All services are defined in a single declarative docker-compose.yml:

• Frontend (React SPA)
• Backend (Express API)
• Nginx (Reverse proxy)
• Shared Docker bridge network

Benefits:

• One-command deployment
• Reproducible environments
• Easy scaling path to Kubernetes

2.2 Service Communication

• Frontend → Nginx → Backend (/api/* routing)
• Backend → External APIs (OpenAI)
• Internal networking via Docker DNS

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3. Containerization Strategy

3.1 Multi-Stage Builds

Both frontend and backend use optimized multi-stage Docker builds:

Frontend pipeline:

1. Build stage (Node + Vite)
2. Production stage (Alpine + Nginx)

Backend pipeline:

• Production-only dependencies
• Minimal Alpine-based runtime

3.2 Optimizations

• Smaller image sizes (~90% reduction)
• No dev dependencies in production
• Reduced attack surface (Alpine base images)
• Layer caching for faster CI builds

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4. Networking & Reverse Proxy

4.1 Nginx Role

• Routes frontend traffic
• Proxies /api requests to backend
• Handles static asset delivery
• Supports WebSocket upgrade headers

4.2 Service Discovery

Uses Docker internal DNS (127.0.0.11) for resolving service names instead of hardcoded IPs.

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5. Deployment Model

Local Development

git clone https://github.com/Anand-Chaudhary/code-review-app.git
cd code-review-app
docker compose up --build

Access: http://localhost:8800

Production Direction

• Kubernetes-ready architecture
• Stateless services enable scaling
• CI/CD pipeline ready structure

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6. CI/CD (Planned)

Target pipeline:

• Lint + test on PR
• Build Docker images
• Push to registry (Docker Hub / ECR)
• Deploy via Kubernetes or VM

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7. Observability (Planned)

Current: stdout logs only

Future upgrades:

• Structured JSON logging
• Prometheus metrics
• Grafana dashboards
• Centralized logging (ELK / Datadog)
• Distributed tracing (OpenTelemetry)

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8. Security Model (Planned Hardening)

• Non-root container execution
• API rate limiting
• TLS via Let’s Encrypt
• Secrets management (Vault / Docker secrets)
• Vulnerability scanning (Trivy)
• Network isolation policies

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9. Scalability Design

Current State

• Single-instance deployment
• Stateless services

Future Scaling

• Horizontal Pod Autoscaling (HPA)
• Multiple backend replicas
• Redis caching layer
• CDN for frontend assets

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10. High Availability (Future)

• Blue-green deployments
• Rolling updates
• Database backups (if DB introduced)
• Multi-region failover (advanced stage)

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11. Tech Stack

Frontend

• React 19
• Vite
• Framer Motion
• PrismJS
• Axios
• React Markdown

Backend

• Node.js 20 (Alpine)
• Express.js
• OpenAI API integration

DevOps

• Docker
• Docker Compose
• Nginx (Alpine)

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12. Engineering Highlights

Strengths

• Multi-stage Docker optimization
• Clean service separation
• Reverse proxy abstraction
• Containerized full-stack deployment

Challenges Solved

• Docker networking via internal DNS
• Image size optimization
• Cross-container routing
• Build caching improvements

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13. Production Readiness Checklist

• Health checks (/health, /ready)
• CI/CD pipeline
• Container registry integration
• Kubernetes manifests
• Rate limiting
• SSL/TLS
• Monitoring + alerting
• Load testing
• Security scanning

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14. Roadmap

Infrastructure

• Kubernetes migration
• HPA autoscaling
• Moving from render to cloud providers
• Multi-region deployment

Observability

• Metrics + tracing
• Centralized logging
• SLO definitions

Performance

• Redis caching
• CDN integration
• API optimization

Security

• mTLS between services
• Secrets vault
• Container hardening

Reliability

• Backup strategy
• Disaster recovery plan
• Blue-green deployments

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15. Contribution Flow

1. Fork repo
2. Create feature branch
3. Run tests locally
4. Submit PR
5. Require review approval

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16. License

MIT License

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17. Maintainer

Engineering Team

Contact: chaudharyaakash234@gmail.com

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Last Updated: May 2026