Snipe Backend Task🧭

📚 | Problem Statement

• Develop a web application using Nest.js featuring a secure authentication system with email-based OTPs, using Firebase Auth and Nodemailer for email functionality. Additionally, implement a dummy user validation system using a predefined array of user objects.

1. Nest.js Application Setup:

• Initialize and configure a new Nest.js project. (You may refer to Nest.js documentation if not done previously)
• Develop necessary routes and middleware for the application.

2. Email-OTP Based Authentication:

• Create a system for generating and validating OTPs for user authentication.

• Set up OTP delivery to the user's email address using Nodemailer.

• Configure Nodemailer for email operations with an SMTP server.

• Design email templates for sending OTPs.

3. User Validation with Dummy User Array:

• Create a dummy array of user objects in the backend. Each object should contain:

• user_id : A unique identifier for the user.

• name : The user's name.

• email : The user's email address.

• Use this array to validate whether a user is valid during the authentication process. Only users in this array should be able to receive an OTP and complete authentication.

4. Testing and Documentation:

• Conduct comprehensive testing.

• Provide clear documentation, including setup and usage instructions.

5. Submission Guidelines:

• Source code in a version-controlled repository.

• README file with setup and running instructions.

• Application with no runtime errors.

• No external database should be used for the same.

• No use of cookies, because the APIs can be used for a mobile app as well.

6. Evaluation Criteria:

• Functionality of authentication and user validation.

• Code quality and adherence to best practices.

• Handling of edge cases and error scenarios.

• Comprehensive documentation.

🎯 | Sample Queries

• POST Url :- http://localhost:3000/auth/sendOTP Body :- "email" : "[email protected]"
• POST Url :- http://localhost:3000/auth/verifyOTP Body :- "email"[email protected]","OTP":"${your_otp}"

🌐 | Test Project

• Clone this repository.
• Install Docker Desktop.
• Create a .env file in the root directory of the web-server folder with credentials EMAIL_USERNAME = "YOUR_EMAIL" EMAIL_PASSWORD = "YOUR_APP_PASSWORD"
• Run docker-compose build in the root directory of the project. This process takes a a minute or two to complete, for the first time.
• Run docker-compose up to initialize web servers running on port 3000.

Features Implemented:

• Dummy user Validation for safety.
• The web service is dockerized to ease out deployment and production.
• The web-service uses NodeMailer SMTP service to send Emails containing OTP.
• Web Service uses in-memory hash table to store otp's for an email until its verified.

Current Architecture:

• Containerized approach to solving the problem statement.
• Given the Non-Blocking and Async Code Execution of NestJS the code doesn't get blocked of delayed due to a resource consuming task.

Future Scope:

• The current architecture is a very basic implementation of the problem statement.
• Depending upon the scale, the entire architecture can be scaled horizontally using nginx load balancing.
• Web can use a queueing mechanism like Rabbit or BullMQ to introduce pub-sub architecture to improve performance.

🧑🏽 | Author

Aditya Sinha

• Linkedin: @Aditya Sinha
• Github: @BREACH1247

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