Build Your Own Web App in 14 Days with AI

Have you studied coding but felt overwhelmed, unsure where to start when trying to build a web app on your own?

You may have learned HTML and CSS and studied a little JavaScript, but when you try to start an actual project, the entire process—from designing the interface to implementing its features—can feel difficult.

In this “Build Your Own Web App in 14 Days with AI” challenge, you will experience firsthand the process of using AI tools such as ChatGPT and GitHub Copilot to define an idea, create screens, implement features, improve your code, and then expand it with React.

The goal is not to learn a lot of content.

The most important goal of this challenge is to complete a small but fully functional web app from start to finish within 14 days.

🚀 This is how the 14-day challenge works

This challenge will be conducted without live classes.

You don’t need to log in at a set time. Simply refer to the provided course materials according to your schedule and complete the missions step by step.

Complete one web app progressively through a total of 6 missions.

Mission 1. Choose Your Own Web App Topic & Set Up the Development Environment
Choose a topic for the web app you want to build and prepare VS Code and the project folder.

Mission 2. Planning Web App Features with AI
Explain the purpose of your project to AI and organize the 3–5 core features to implement within 14 days.

Mission 3. Create the basic web app interface with HTML and CSS
Build the basic UI for the features using HTML and CSS, including a search bar, buttons, and card lists.

Mission 4. Build Functional Features with JavaScript
Add actual functionality to the interface, such as search, filters, and button events.

Mission 5. Improve Code with AI
Have AI review the code you wrote, then directly improve redundant code, variable names, function structure, and more.

Mission 6. Expand the Web App with React
Convert your completed HTML·CSS·JavaScript project to React and gain hands-on experience with useState and component structure.

🤖 You don’t have to write all the code yourself.

In this challenge, you will actively leverage AI.

Simply asking AI to

"Generate the code for me"

Rather than stopping at simply asking, “Please create the code,”

• Explain the current project situation and

• We request the feature we want to implement in specific terms and

• Run the generated code and

• When a problem occurs, ask about its cause and

• Requesting ways to improve the code again

Repeat the process.

Through this, you can experience how to use AI not merely as a code generator, but as a tool for developing together.

💡 What projects can you create?

You can choose any topic you like.

For example, you can create web apps such as the following.

• Product discovery web app

• Movie search web app

• Travel destination exploration web app

• TODO Web App

• Portfolio web app

• Collection of Content of Interest

• A Simple Web App Using Your Own Idea

You don't need to build a complex service from the start.

Rather than features with a large implementation scope, such as sign-up, payments, and real-time chat, start by implementing features like search, filters, lists, and button events, where you can directly see the results.

📚 Step-by-step learning materials are provided

Each mission comes with step-by-step learning materials explaining how to complete it.

Rather than simply assigning a task by saying, “Try creating this feature,”

STEP 1 → STEP 2 → STEP 3

It is structured so that you can complete the mission by following the materials in order.

We also provide example AI prompts and a checklist you can use when you get stuck while coding.

Therefore, even if you felt overwhelmed by starting a project on your own, you can proceed by following along step by step.

✅ Recommended for these learners

• If you’ve learned HTML and CSS but aren’t sure what to do next

• Those who have studied JavaScript syntax but lack project experience

• Those who are curious about how to use ChatGPT or Copilot for coding

• Those who want to create something themselves rather than just keep listening to lectures

• Those who want to experience the overall development workflow before seriously studying React

• Those who want to experience a new way of developing by coding together with AI

If you have studied the basic structure of HTML and CSS at least once, you’ll be able to follow along more easily.

You don’t need to have a perfect understanding of JavaScript and React.

⏱ You can proceed at your own pace without feeling overwhelmed.

The total duration is 14 days, and there are 6 required missions.

Rather than completing a new mission every day, the program is structured so that you can work on a single mission for 1–2 days.

Each mission is designed to take approximately 20–50 minutes, with time set aside in between to catch up on anything you were unable to complete.

Office workers and those with irregular schedules can participate according to their own availability.

🏁 What will remain after 14 days?

Upon completing this challenge, you’ll be left with more than just a record of having taken a course.

Directly

You will choose an idea → plan the features → create the screens → implement functionality with JavaScript → improve the code with AI → expand it with React

You’ll experience the entire process.

And at the end,

"One web app I completed myself"

will remain.

The goal is not to create a perfect project.

Even if it’s small, the experience of completing it yourself from start to finish is the best starting point for beginning your next project.

🚀 After completing the challenge, take the next step in your growth!

Congratulations!
Through this challenge, you experienced the process of defining an idea, creating screens with AI, implementing JavaScript functionality, and expanding it with React.

Now, building on your hands-on experience, strengthen your understanding of the fundamentals and expand your learning to React and real-world projects.

1️⃣ If you want to properly understand the fundamentals of JavaScript

In the challenge, you quickly implemented the JavaScript functionality you needed with AI. Now it’s time to systematically learn core concepts such as variables, arrays, objects, functions, the DOM, and events.

2️⃣ If you want to learn React as the next step after JavaScript

In the challenge, you gained a light introduction to components and state management by converting a screen built with HTML/JavaScript into React.

Now, learn React’s structure and core concepts step by step from the beginning.

3️⃣ If you want to build a real-world service from start to finish with React

If you’ve learned the basic concepts of React, you can now take on a project that stores and manages real data.

Using React and Firebase, build a complete project by implementing features used in real web services, such as authentication, databases, and image uploads.

🌱 Continue learning with this next step

14-Day Web App Challenge
→ Experience the entire process by building it yourself

JavaScript basics
→ Understand the principles behind the code you used

Your First React Experience
→ Learn core React concepts and development practices

React + Firebase Hands-On Project
→ Complete a real-world, production-level project

The web app you built in this challenge is not the end, but your first project.

You don’t need to know everything from the start to develop.
Your development skills will grow by repeating the process of building things yourself, studying what you lack, and adding new features.

Now, take the next step beyond “follow-along learning” and continue learning by building and expanding things yourself. 🚀