How long does it take to build a site like Udemy or Coursera?

I am assuming you are already aware of the basic things you should keep in mind while building a site like Coursera or Udemy. So let us first discuss the things you need to develop so that we can derive the time to develop the features and technology stack for that.

What needs to be developed for an e-learning site and app

1. Admin Panel

· Login

· Forgot Password system

· Grade Management

· Subject Management

· Content Management

· Test / Exam Management

· Student / Parent Management

· Contest Management

· Payment Management

· Query Solution

· CMS Management

· Dashboard

· Report

· Notifications

· Logout

2. Learners Android & iOS App

· Signup / Login

· Profile Management

· Subject Detail Screen

· Quizzes

· Contest

· Payment

· Chat

· Push Notification

· Contact Tutor / Admin

· CMS

· Logout

3. Tutor Android & iOS Apps

· Register / Login

· Connect with Student

· Content Upload & Management

· Notification Tab

· Profile Management

· View Students Activity

· Assign work to students

· Student Report Generation

· Contact Admin

· Logout

4. Backend Development

· Database Design

· Application Design

· Web Service

· Server Setup & Configuration

· Deployment

5. Miscellaneous Work

· Business Analysis

· Project Management

· Quality Assurance

Hope the derived development timeline helps you get a detailed guide on e-learning platform development.