How I Built and Shipped My First MVP: A Full-Stack Developer‘s Journey

Shipping your first minimum viable product (MVP) is a major milestone for any developer. It‘s the culmination of taking an idea from concept to reality, overcoming both technical and mental hurdles along the way.

Three months ago, I achieved this milestone myself with the launch of CodeBites, an interactive web app that gamifies the process of learning to code. As an experienced full-stack developer, I thought I was prepared for the challenges of MVP development – but there were still many lessons to be learned.

In this post, I want to take you behind-the-scenes of how I built and launched CodeBites, from defining the initial scope to fixing bugs post-launch. I‘ll dive deep into the technical architecture, share code snippets of tricky problems, and provide data-driven insights on the process. My goal is to create a comprehensive resource for developers embarking on their own MVP journey.

Defining the MVP Scope

The idea for CodeBites had been percolating in my mind for almost a year before I committed to building an MVP. I had pages of notes on features I wanted to include, from social elements to mobile push notifications. But I knew that if I tried to do everything at once, I‘d never ship.

To constrain my scope, I went back to basics and defined a single user story that represented the core journey:

As a coding beginner, I want to improve my JavaScript skills by completing short interactive lessons and tracking my progress over time.

Everything in my initial feature set laddered up to enabling this story:

• User registration and authentication
• Lesson interface with code editor and output preview
• Points system to gamify progress
• Dashboard to track completed lessons and total points

Anything that didn‘t directly contribute to this core journey was stripped out. Building an MVP is all about exercising restraint and embracing the idea that less is more.

Planning the Architecture

With my feature set defined, I started to sketch out the technical architecture. The key decision was how to structure the app and what tools to leverage.

As a full-stack developer specialized in JavaScript, the MERN stack (MongoDB, Express, React, Node.js) has been my go-to for most projects. But for CodeBites, I wanted to move fast and minimize backend overhead. So instead of spinning up my own API and database, I chose to build on top of Firebase.

The frontend would be a React app, created with Next.js and deployed to Vercel. Vercel‘s serverless functions would handle any necessary API routes, making calls to Firebase.

Firebase Authentication would power user management, with its robust and secure OAuth system. All other data, from user progress to lesson content, would be stored in a Firestore NoSQL database.

This architecture provided several advantages:

• Abstracts away infrastructure management and scaling
• Simplifies the code base with fewer moving pieces
• Enables rapid iteration and deployment of changes
• Provides out-of-the-box functionality like auth guards

Of course, it also came with tradeoffs like vendor lock-in and less granular control. But I wasn‘t trying to build a resilient platform – I was trying to validate an idea. Speed and simplicity trumped long-term maintainability.

Diving Into Development

With architecture decided, it was time to get my hands dirty and start coding. I committed to working on CodeBites in focused sprints, dedicating 2-3 hours each evening after work and more time on weekends.

Adopting an agile approach, I would pick off features one by one, moving them across a simple Kanban board from "To Do" to "In Progress" to "Done". I also kept a separate list of bugs and enhancements filed by beta testers.

The development Kanban board halfway through the MVP build.

In total, the MVP build took 7 weeks from first commit to launch. In that time, I:

• Wrote 10,842 lines of code across 93 files
• Committed 178 times with an average of 61 new lines per commit
• Resolved 46 distinct user stories and squashed 23 bugs
• Spent an average of 19.6 hours per week actively developing

While the bulk of the app came together smoothly, there were a few hairy technical challenges along the way that ate up disproportionate time and mental energy.

The Auth Gauntlet

Implementing user authentication with Firebase Auth and Next.js was more complex than anticipated. I needed to share the authenticated user object between client and server-side rendered pages while guarding each route individually.

To solve this, I created an AuthProvider Context component that would initialize the Firebase SDK and populate the user object. The magic line was:

const userObj = await firebaseClient.auth().currentUser;

I then created a higher-order function called withAuth which would wrap each guarded page component, check for the existence of userObj, and redirect to login if empty.

export function withAuth(Component) {
  return function WithAuth(props) {
    const { user } = useAuth();

    if (!user) {
      return <Login />;
    }

    return <Component auth={user} {...props} />;
  };
}

To use this on a page, I would simply export the wrapped component:

export default withAuth(ProfilePage);

Taming the Code Editor

The heart of CodeBites is the lesson interface, where users can write and execute real JavaScript code. I knew I wanted a setup with a code editor on the left and an output preview on the right, similar to CodePen.

An early version of the lesson interface, with Monaco as the editor.

For the editor, I first tried Monaco, the same editor that powers VS Code. But its bundle size and complex API were overkill for this use case. I then switched to CodeMirror which provided a lighter-weight option.

Rendering the output preview securely was its own challenge. I needed to execute the user‘s code in a sandboxed environment and display the results. To do this, I spun up a hidden iframe and used postMessage to communicate between the parent window and the iframe.

const createIframe = () => {
  const iframe = document.createElement(‘iframe‘);
  iframe.style.display = ‘none‘;

  document.body.appendChild(iframe);

  return iframe;
};

// Parent window
const iframe = createIframe();
iframe.contentWindow.postMessage(code, ‘*‘);

// Iframe
window.addEventListener(‘message‘, (event) => {
  const code = event.data;
  try {
    eval(code);
  } catch (error) {
    console.error(error);
  }
});

This approach had its limitations – the iframe couldn‘t access the DOM of the main window. But it was good enough for executing basic JavaScript and logging the output to the console.

Atomic Achievements

One of the core gamification elements of CodeBites is earning points for completing lessons. I wanted these points to be awarded immediately upon lesson completion, which posed a challenge.

The naive approach would be to simply increment the user‘s point total when they submit their code and it passes all test cases. But this could lead to race conditions and over-awarding of points if, for example, the user double-clicked the submit button.

To solve this, I used a Firestore transaction to update the user‘s point balance and mark the lesson as complete in a single atomic operation.

const completeLessonTransaction = async (lessonId, userId) => {
  const db = firebase.firestore();
  const userRef = db.collection(‘users‘).doc(userId);
  const lessonRef = db.collection(‘lessons‘).doc(lessonId);

  return db.runTransaction(async (transaction) => {
    const userDoc = await transaction.get(userRef);
    const lessonDoc = await transaction.get(lessonRef);

    if (!userDoc.exists || !lessonDoc.exists) {
      throw new Error(‘User or lesson does not exist‘);
    }

    const lesson = lessonDoc.data();
    const user = userDoc.data();

    if (user.completedLessons.includes(lessonId)) {
      throw new Error(‘Lesson already completed‘);
    }

    const newUserData = {
      points: user.points + lesson.points,
      completedLessons: [...user.completedLessons, lessonId],
    };

    transaction.update(userRef, newUserData);
  });
};

This ensures that no matter how many times the user clicks submit, they will only receive points once per lesson. Transactions are a powerful tool for maintaining data integrity, especially in a NoSQL context.

Gathering Feedback and Iterating

With core functionality in place, I started sharing CodeBites with fellow developers to gather feedback. I recruited a group of 10 beta testers who agreed to use the app and provide detailed notes on their experience.

The feedback was humbling and illuminating. While testers liked the overall concept, they had a laundry list of ways to improve the user experience:

• Add a way to save progress mid-lesson
• Provide more granular feedback on incorrect code submissions
• Enable a split-screen view to see instructions and code side-by-side
• Improve the clarity and specificity of error messages
• Expand onboarding and add a product tour for first-time users

I aggregated this feedback and triaged each suggestion by its potential impact and required effort. The high-impact, low-effort items became my punch list for the last week of development before launch.

Bucketing feedback into a prioritization matrix.

One of the most effective additions was a "Report a Problem" widget that allowed users to submit issues without leaving the app. I used FeedBear to power this, which provided an easy way to track bugs and route them to my development backlog.

Measuring the Launch

After a final QA pass and some pre-launch jitters, I officially released CodeBites to the world. I posted links on Twitter, LinkedIn, Product Hunt, and a few other channels. Then, I sat back and waited anxiously to see how the world would receive my creation.

The launch exceeded my expectations, with over 500 users signing up in the first week. Engagement was also strong – 78% of users completed at least one lesson, and 23% made it all the way through the initial 5 lesson track.

Metric	Week 1	Week 2	Week 3	Week 4
Total sign-ups	512	901	1,217	1,644
Lessons started	823	1,419	2,204	2,918
Lessons completed	502	921	1,509	2,106
Completion rate	61%	65%	68%	72%
Average points earned	87	106	118	128
Average time per lesson	12 min	14 min	15 min	16 min

Key usage metrics for the first 4 weeks post-launch.

Of course, not everything went smoothly. A few eager users found edge cases I hadn‘t accounted for, like trying to complete the same lesson multiple times in a row. These bugs resulted in 27 user-reported issues in the first week, which I scrambled to patch.

But overall, the launch validated the core hypothesis behind CodeBites – that there was appetite for a more engaging and interactive way to learn coding online. It was immensely gratifying to see real people using and finding value in something I had created.

The Road Ahead

Shipping an MVP is just the first step in a longer product journey. In the months since launch, I‘ve continued to gather feedback, prioritize features, and iterate on CodeBites. Some of the key initiatives on the roadmap include:

• Expanding the curriculum with new lessons and tracks
• Adding user profiles and social sharing of progress
• Enabling user-submitted content and challenges
• Improving accessibility and mobile responsiveness
• Implementing a spaced repetition system to reinforce concepts
• Exploring monetization options like a premium tier

But beyond specific features, my focus is on continuing to deliver an exceptional learning experience to the CodeBites community. This means obsessing over feedback, proactively communicating updates, and never losing sight of the core mission.

It also means continuing to invest in personal growth as a full-stack developer. With each new challenge, I have an opportunity to deepen my expertise and expand my toolkit. Currently, I‘m diving into Recoil as a more performant state management solution and Cypress for end-to-end testing.

Lessons and Advice

Shipping your first MVP is a major accomplishment worth celebrating. It‘s also a powerful learning experience that will make you a better developer. Here are a few of the key lessons I‘ve taken away:

1. Scope aggressively and ship quickly. It‘s easy to get caught up in edge cases and nice-to-haves, but the most important thing is getting your core product in front of users. You can always iterate and expand later.

2. Embrace imperfection. Your MVP will have bugs and rough edges – that‘s okay. The goal is to validate your concept and start gathering feedback, not to launch a flawless product. Done is better than perfect.

3. Leverage tools that accelerate development. Look for opportunities to offload undifferentiated heavy lifting to managed services and proven libraries. Ideally, you should spend most of your time on code that is unique to your product.

4. Prioritize the user experience. It doesn‘t matter how elegant your code is if users can‘t figure out how to use your app. Invest time in getting the small details right, from microcopy to error handling.

5. Instrument analytics from day one. You can‘t improve what you don‘t measure. Integrate event tracking and logging early so you can understand how users are actually interacting with your product.

6. Plan for scale but don‘t over-engineer. Design your architecture with room to grow, but resist the urge to prematurely optimize. You may need to make major changes based on user feedback, so stay nimble.

7. Foster a community around your product. Some of the most valuable feedback and insights will come from engaged users. Make it easy for them to share their thoughts and connect with each other.

To all the developers out there working on their own MVP, I hope this post has provided some guidance and inspiration. Building a product from scratch is never easy, but it‘s incredibly rewarding to see your vision come to life and touch the lives of real people.

If you‘re interested in following along with the continued journey of CodeBites, you can check out the site at codebites.io or follow me on Twitter at @mikesmith. I‘d love to connect with more developers and trade war stories.

And if you‘re looking for more tactical advice on MVP development, I highly recommend the following resources:

• The Lean Startup by Eric Ries
• Getting Real by 37signals
• The Mom Test by Rob Fitzpatrick

Here‘s to all the makers, shippers, and innovators out there. Keep building!