Internship Management Backend API

A powerful Node.js + Express.js backend for managing internship applications and verifying digital certificates. Built for scale, speed, and simplicity — this API integrates seamlessly with Google Sheets and MongoDB for efficient data storage and lookup.

Demo Video

Demo.backend.API.mp4

Features

• Internship Application Submission

  • Validates incoming data from students
  • Securely stores applications to Google Sheets using the Google Sheets API
  • Duplicate detection based on contact number

• Certificate Management & Verification

  • Admin-only route to add certificates (protected by API key)
  • Fast certificate lookup by unique certId
  • MongoDB-powered schema for flexible certificate structure

• Security & Middleware

  • Helmet for HTTP headers security
  • CORS enabled
  • API-key-based admin protection
  • Centralized input validation

Tech Stack

Layer	Technology
Server	Node.js + Express
Database	MongoDB + Mongoose
Spreadsheet	Google Sheets API
Auth (Admin)	API Key
Validation	Express Validator

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Installation

git clone https://github.com/your-username/internship-backend.git

cd internship-backend
npm install

Create .env file:

PORT=3000
MONGO_URI=mongodb+srv://your-cluster.mongodb.net/db-name
GOOGLE_SHEET_ID=your_google_sheet_id
ADMIN_API_KEY=supersecureadminkey

Add google-credentials.json

Create a Google Service Account and place your credentials JSON file at the root or in a /config directory. Don’t forget to share your sheet with the service account email!

To Run the Server

npm run dev

API Endpoints

Internship Application

Method	Endpoint	Description
POST	/api/apply	Submit internship application

Admin Certificate Management

Method	Endpoint	Description
POST	/api/certificates	Add a new certificate

Headers:

api-key: <your-admin-api-key>

Certificate Verification

Method	Endpoint	Description
GET	/api/certificates/verify/:certId	Get certificate by ID

Example Request

POST /api/apply

{
  "name": "Ritika Gupta",
  "gender": "Female",
  "age": 22,
  "contactNumber": "9876543210",
  "college": "Pawan Institute of Tech",
  "collegeAmbassador": true,
  "domain": "Web Development",
  "linkedinFollowed": true,
  "screenshot": "screenshot_url_or_file",
  "referrerName": "Ayush Sinha",
  "agreedToTerms": true
}

Upcoming Features

• Email confirmations to applicants
• Document upload uploads
• PDF Certificate Generator (Like Courcera)