DEPLOYMENT_GUIDE.md

🚀 Deployment Guide

This guide will walk you through deploying your backend to free hosting platforms.

📋 Prerequisites

Before deploying, ensure you have:

• ✅ GitHub account
• ✅ Redis Cloud account (already set up)
• ✅ All code committed to GitHub
• ✅ .env file configured locally (DO NOT commit this!)

🎯 Option 1: Deploy to Render (Recommended)

Why Render?

• ✅ Free tier available
• ✅ Auto-deploys from GitHub
• ✅ Easy environment variable management
• ✅ Good for Node.js apps

Step-by-Step Instructions

1. Create GitHub Repository

# Initialize git (if not already done)
git init

# Add all files
git add .

# Commit
git commit -m "Initial commit: Real-time DEX aggregator"

# Create repository on GitHub, then:
git remote add origin https://github.com/YOUR_USERNAME/YOUR_REPO_NAME.git
git branch -M main
git push -u origin main

2. Sign Up for Render

1. Go to render.com
2. Click "Get Started for Free"
3. Sign up with GitHub (easiest option)

3. Create New Web Service

1. Click "New +" → "Web Service"
2. Connect your GitHub repository
3. Select your realtime-dex-aggregator repo
4. Configure:
   • Name: dex-aggregator (or your choice)
   • Region: Choose closest to you
   • Branch: main
   • Root Directory: Leave blank
   • Runtime: Node
   • Build Command: npm install && npm run build
   • Start Command: npm start
   • Instance Type: Free

4. Add Environment Variables

In Render dashboard:

1. Go to "Environment" tab
2. Add these variables:
   • REDIS_URL: redis://default:YOUR_PASSWORD@redis-17448.c258.us-east-1-4.ec2.cloud.redislabs.com:17448
   • NODE_ENV: production

5. Deploy!

1. Click "Create Web Service"
2. Wait for deployment (5-10 minutes)
3. Your app will be live at: https://YOUR_APP_NAME.onrender.com

6. Test Your Deployment

# Test REST API
curl https://YOUR_APP_NAME.onrender.com/api/tokens?q=SOL

# Test in browser
https://YOUR_APP_NAME.onrender.com/api/tokens?q=SOL

---

🎯 Option 2: Deploy to Railway

Why Railway?

• ✅ Very simple setup
• ✅ Free $5/month credit
• ✅ Built-in Redis option
• ✅ Great developer experience

Step-by-Step Instructions

1. Create GitHub Repository (Same as Render)

git init
git add .
git commit -m "Initial commit"
git remote add origin https://github.com/YOUR_USERNAME/YOUR_REPO_NAME.git
git push -u origin main

2. Sign Up for Railway

1. Go to railway.app
2. Click "Login" → "Login with GitHub"
3. Authorize Railway

3. Create New Project

1. Click "New Project"
2. Select "Deploy from GitHub repo"
3. Choose your repository
4. Railway will auto-detect Node.js

4. Add Environment Variables

1. Click on your service
2. Go to "Variables" tab
3. Add:
   • REDIS_URL: Your Redis connection string
   • PORT: Railway auto-assigns, but you can set to 3000

5. Deploy!

1. Railway automatically deploys
2. Click "Settings" → "Generate Domain"
3. Your app will be at: https://YOUR_APP.up.railway.app

---

🎯 Option 3: Deploy to Fly.io

Quick Setup

# Install Fly CLI
curl -L https://fly.io/install.sh | sh

# Login
fly auth login

# Launch app
fly launch

# Set environment variables
fly secrets set REDIS_URL="your-redis-url"

# Deploy
fly deploy

---

🧪 Post-Deployment Testing

1. Test REST API

# Replace with your actual URL
curl https://YOUR_APP.onrender.com/api/tokens?q=SOL

Expected: JSON array of tokens

2. Test WebSocket

Open index.html and update the connection URL:

const socket = io('https://YOUR_APP.onrender.com');

3. Test Multiple Requests

# Test 5 rapid requests
for i in {1..5}; do
  curl https://YOUR_APP.onrender.com/api/tokens?q=SOL
  echo "\n---\n"
done

4. Monitor Logs

Render:

• Dashboard → Your Service → "Logs" tab

Railway:

• Click your service → "Deployments" → View logs

---

📝 Update README with Live URL

After deployment, update your README.md:

## 🌐 Live Demo

**API Endpoint:** `https://YOUR_APP.onrender.com/api/tokens?q=SOL`

**WebSocket:** Connect to `https://YOUR_APP.onrender.com`

---

🐛 Troubleshooting

Issue: "Application failed to start"

Solution:

1. Check logs for errors
2. Verify npm start runs node dist/server.js
3. Ensure npm run build creates dist/ folder

Issue: "Cannot connect to Redis"

Solution:

1. Verify REDIS_URL environment variable is set
2. Check Redis Cloud is accessible (not IP-restricted)
3. Test connection locally first

Issue: "Port already in use"

Solution:

• Use process.env.PORT || 3000 in your code
• Hosting platforms assign ports automatically

Issue: "WebSocket not connecting"

Solution:

1. Ensure CORS is enabled
2. Check WebSocket URL uses https:// not http://
3. Verify Socket.io client version matches server

---

🎬 Recording Demo Video

What to Show (1-2 minutes)

1. API Call (20 seconds)

   • Show curl command
   • Display JSON response
   • Highlight response time

2. WebSocket Demo (30 seconds)

   • Open 2-3 browser tabs with index.html
   • Show real-time updates in all tabs simultaneously

3. Architecture Explanation (40 seconds)

   • Show diagram
   • Explain: Client → API → Aggregator → Cache → External APIs

4. Code Walkthrough (30 seconds)

   • Show aggregator.ts merging logic
   • Explain caching strategy

Tools for Recording

• Windows: OBS Studio (free)
• Mac: QuickTime or ScreenFlow
• Online: Loom (easiest)

Upload to YouTube

1. Record video
2. Upload to YouTube (unlisted or public)
3. Add link to README

---

✅ Final Checklist

Before submitting:

• Code pushed to GitHub with clean commits
• Deployed to free hosting (Render/Railway)
• Public URL added to README
• Environment variables configured
• API tested and working
• WebSocket tested with multiple tabs
• Demo video recorded and uploaded
• Postman collection created
• Unit tests written (≥10 tests)
• README documentation complete

---

🎉 You're Done!

Your backend is now live and accessible from anywhere in the world! 🌍

Next Steps:

1. Share the URL with your interviewer
2. Monitor logs for any issues
3. Consider adding more features (rate limiting, authentication, etc.)