🚀 Interview Experiences API

A robust, type-safe, and highly scalable RESTful API built to share, manage, and explore technical interview experiences.

CLEAN CODE • FEATURE-BASED ARCHITECTURE • STRONGLY TYPED

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🟢 Live API URL: https://interview-experiences-api.onrender.com/

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💡 What is this?

The Interview Experiences API is a backend service designed to empower professionals and freshers to document and learn from technical interview encounters. Built with a strict TypeScript foundation, this API leverages Express.js for routing, JWT for authentication, Prisma ORM for seamless database interactions with PostgreSQL, and Zod for bulletproof data validation.

✨ Key Features

• 🔐 Secure Authentication: JWT-based authentication with secure, HTTP-only cookie delivery and password hashing using bcryptjs.
• 🛡️ Strict Type Safety & Validation: End-to-end type safety. Every request parameter, query, and body is rigorously validated at runtime using dedicated Zod middlewares.
• 🏗️ Feature-Driven MVC Architecture: Code is logically grouped by feature (auth, users, experiences, comments, tags) rather than by generic types, promoting incredible scalability and maintainability.
• 🚦 Centralized Error Handling: A global error handler that seamlessly intercepts and standardizes database errors, validation errors, and custom operational exceptions.

🛠️ Tech Stack

Category	Technology
Runtime / Core	Node.js, TypeScript
Web Framework	Express.js (v5)
Database & ORM	PostgreSQL, Prisma
Validation	Zod
Security & Auth	JSON Web Tokens (JWT), bcryptjs, cookie-parser

🚦 Request Processing Pipeline

The API operates a unidirectional pipeline to ensure no corrupt or unauthenticated execution blocks hit your business logic.

%%{init: {'themeVariables': { 'fontSize': '15px' }}}%%
graph TD
    subgraph MainFlow [ Main Flow ]
        direction LR
        A([ HTTP Request ]) --> B[ Express Router ]
        B --> C[ JWT Middleware ]
        C --> D[ Zod Validator ]
        D --> E[ Controller ]
        E --> F[ Service ]
        F --> G[ Repository ]
        G --> H[( PostgreSQL )]
    end

    I> Global Error Handler ]

    C -.->| Auth Error | I
    D -.->| Validation Error | I
    E -.->| App Error | I
    F -.->| App Error | I
    G -.->| Prisma Error | I

    style I fill:#fef2f2,stroke:#e11d48,stroke-width:2px,color:#be123c

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🛡️ Data Validation & Error Handling

This API implements a resilient, crash-proof error-handling strategy directly tied into the pipeline above:

• Zod Validation (middlewares/zod.ts): Automatically intercepts bad requests before they reach the controller, returning detailed field-level error messages (e.g., 400 Bad Request).
• Global Error Handler (middlewares/error.handler.ts): Catches all unhandled exceptions, formats Prisma database errors (like P2002 unique constraint violations or P2025 record not found), and ensures a standard JSON response structure is always returned to the client.
• Custom AppError: Thrown within services for business logic constraints (e.g., 403 Forbidden if a user tries to edit an experience they don't own).

🗄️ Database Schema

The database is built on PostgreSQL with Prisma managing the relational integrity.

%%{init: {'themeVariables': { 'fontSize': '12px'}}}%%
erDiagram
    USER ||--o{ EXPERIENCE : creates
    USER ||--o{ COMMENT : writes
    USER ||--o{ TAG : creates
    EXPERIENCE ||--o{ COMMENT : has
    EXPERIENCE }o--o{ TAG : categorized_by

    USER {
        Int id PK
        String name
        String email UK
        String password
        Int age
        Int yearsOfExperience
        String current_role
        String industry
    }
    EXPERIENCE {
        Int id PK
        Int userId FK
        String company
        String role
        Int roundsCount
        Int difficulty
        Enum outcome
        String content
        DateTime interviewDate
    }
    COMMENT {
        Int id PK
        Int userId FK
        Int experienceId FK
        String comment
    }
    TAG {
        Int id PK
        String tagName UK
        Int createdByUserid FK
        DateTime addedOn
    }

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🚀 Getting Started

Prerequisites

• Node.js (v18 or higher recommended)
• PostgreSQL installed and running locally.

Installation & Setup

1. Clone & Install:

git clone [https://github.com/iamkgehlot/interview-experiences-api.git](https://github.com/iamkgehlot/interview-experiences-api.git)
cd interview-experiences-api
npm install

2. Database & Environment:

Setup your .env file, then run migrations:

npx prisma generate
npx prisma migrate dev
npm run dev

📡 API Endpoints Summary

All routes are prefixed with /api. Note: Protected endpoints require a valid JWT token.

Method	Endpoint	Description	Protected
POST	/api/register	Register a new user	❌
POST	/api/login	Login & receive JWT cookie	❌
POST	/api/logout	Clear auth cookies	❌
GET	/api/users	Fetch all users	🔒
GET	/api/users/:id	Fetch specific user	🔒
PATCH	/api/users/:id	Update user profile	🔒
GET	/api/experiences	Fetch all experiences	🔒
GET	/api/experiences/:experienceId	Fetch specific experience	🔒
GET	/api/users/:userId/experiences	Fetch user's experiences	🔒
POST	/api/users/:userId/experiences	Create a new experience	🔒
PATCH	/api/experiences/:experienceId	Update an experience	🔒
GET	/api/experiences/:experienceId/comments	Get comments for an experience	🔒
GET	/api/users/:userId/comments	Get all comments by user	🔒
POST	/api/experiences/:experienceId/comments	Add comment to an experience	🔒
PATCH	/api/comments/:commentId	Update a comment	🔒
GET	/api/tags/	Get all tags	🔒
GET	/api/tags/:tagId	Get tag by ID	🔒
POST	/api/tags/	Create a tag	🔒
PATCH	/api/tags/:tagId	Update a tag	🔒
DELETE	/api/experiences/:experienceId	Delete an experience	🔒
DELETE	/api/comments/:commentId	Delete a comment	🔒
DELETE	/api/tags/:tagId	Delete a tag	🔒
DELETE	/api/users/:id	Delete user profile	🔒

Engineered with Precision & Energy ⚡