Let me start with a confession: I’ve reinvented more wheels than a medieval blacksmith having an existential crisis. And you know what? I regret absolutely nothing. If you’ve been in the software development game for more than five minutes, you’ve probably heard the sacred mantra echoing through conference halls and code reviews alike: “Don’t reinvent the wheel!” It’s delivered with the same reverence usually reserved for ancient wisdom, often followed by a knowing nod and the swift installation of yet another 47MB dependency to center a div. But here’s the thing – sometimes that wheel is square, sometimes it’s made of cheese, and sometimes it’s not even a wheel but a confused hexagon pretending to be circular. Today, we’re going to explore why challenging the orthodoxy of code reuse might just make you a better developer (and possibly a more annoying teammate, but we’ll cross that bridge when we get to it).

The Comfort Zone Conspiracy

The “don’t reinvent the wheel” mentality often stems from a place of comfort rather than wisdom. Engineers become invested in familiar frameworks and resist learning new approaches, even when existing solutions cause bloat, poor architecture, or performance issues that ultimately harm the end user. Think about it: when was the last time you questioned whether that utility library you pulled in for a single function was really worth the 200KB bundle size increase? Or when you spent three hours debugging a third-party component when a custom solution would have taken two hours to write and would actually work the way you need it to?

graph TD A[New Feature Required] --> B{Check npm} B --> C[Found 47 Libraries] C --> D[Pick Most Popular One] D --> E[Install 23 Dependencies] E --> F[Bundle Size +500KB] F --> G[Feature Almost Works] G --> H[Spend 2 Days Debugging] H --> I[Consider Custom Solution] I --> J[Too Late, Ship It]

The reality is that browser APIs have evolved dramatically. We have incredible tools baked right into modern browsers that many JavaScript libraries completely ignore. Yet we continue to download the internet one package at a time because, well, “don’t reinvent the wheel.”

The Learning Paradox

Here’s where things get interesting. The people who tell you not to reinvent the wheel are often the same ones who originally invented the wheels you’re now using. They learned by doing, by experimenting, by making mistakes and building solutions from scratch. When you adopt open source tools without understanding their internals, you’re often signing up for a mystery box experience. The README shows you the happy path, but what happens when you hit that edge case that the maintainer never considered? Suddenly you’re digging through optimized, unfamiliar code, trying to understand why your perfectly reasonable use case is causing everything to explode. The willingness to architect and implement custom solutions might be one key difference between senior and junior engineers. It’s about understanding when the cost of learning and maintaining a custom solution is worth the benefits of having exactly what you need.

When Reinvention Makes Sense

Let’s get practical. Here are some scenarios where rolling your own solution isn’t just acceptable – it’s smart:

Performance-Critical Applications

If you’re building a real-time trading platform, you probably don’t want to include a 50KB animation library just to make your buttons bounce. Sometimes a few lines of custom CSS will do the job better, faster, and with less overhead.

// Instead of importing an entire lodash for one function
import { debounce } from 'lodash'; // +50KB
// Consider this lightweight alternative
function debounce(func, delay) {
  let timeoutId;
  return function (...args) {
    clearTimeout(timeoutId);
    timeoutId = setTimeout(() => func.apply(this, args), delay);
  };
}
// +0.1KB and you know exactly what it does

Highly Specific Business Logic

Generic solutions are, by definition, generic. If your business has unique requirements that represent your competitive advantage, a custom solution might be the way to go.

Learning and Skill Development

Want to understand how state management works? Build a mini-Redux. Curious about virtual DOMs? Create a simple version. You’ll gain insights that no amount of documentation reading can provide.

Long-term Maintenance

Sometimes maintaining your own 100-line solution is easier than keeping up with a library’s breaking changes every six months. Especially when you only use 2% of the library’s features.

A Step-by-Step Approach to Smart Reinvention

Here’s a framework I use when deciding whether to build or buy:

Step 1: Define Your Exact Needs

Be specific. Write down exactly what you need the solution to do. Not what might be nice to have, not what the popular library does – what YOU need.

// Bad: "I need a date library"
// Good: "I need to format dates in ISO format and calculate 
//       differences in business days for timezone-aware scheduling"

Step 2: Estimate the Custom Solution

How long would it take you to build exactly what you need? Be honest, add a buffer for debugging and edge cases.

Step 3: Evaluate Existing Solutions

Look at the popular options. Check their:

  • Bundle size and dependencies
  • API surface area (how much you’ll actually use)
  • Maintenance status and community health
  • License compatibility
  • Performance characteristics

Step 4: Calculate the Total Cost of Ownership

graph LR A[Initial Setup Time] --> B[Learning Curve] B --> C[Integration Complexity] C --> D[Ongoing Updates] D --> E[Support/Debug Time] E --> F[Migration Risk] F --> G[Total Cost] H[Custom Development] --> I[Testing Time] I --> J[Documentation] J --> K[Maintenance] K --> L[Team Knowledge Transfer] L --> M[Total Cost]

Step 5: Make the Decision

If the custom solution wins, build it. If the existing solution wins, use it. But make this decision consciously, not by default.

Real-World Examples: When I Chose Reinvention

Let me share a few war stories where reinventing the wheel paid off:

The Case of the Bloated Form Validator

I once worked on a project where the existing form validation library was 180KB minified. Our needs were simple: validate email format and ensure required fields weren’t empty. The custom solution:

const validators = {
  required: (value) => value.trim() !== '',
  email: (value) => /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(value)
};
function validateForm(formData, rules) {
  const errors = {};
  Object.keys(rules).forEach(field => {
    const value = formData[field] || '';
    const fieldRules = rules[field];
    fieldRules.forEach(rule => {
      if (!validators[rule](value)) {
        errors[field] = errors[field] || [];
        errors[field].push(`${field} ${rule} validation failed`);
      }
    });
  });
  return {
    isValid: Object.keys(errors).length === 0,
    errors
  };
}
// Usage
const result = validateForm(
  { email: '[email protected]', name: '' },
  { email: ['required', 'email'], name: ['required'] }
);

Result: 2KB instead of 180KB, perfect fit for our needs, and the entire team understood how it worked.

The State Management Rebellion

On another project, we were using a complex state management library for what amounted to sharing a few values between components. The custom solution using the browser’s built-in BroadcastChannel API:

class SimpleState {
  constructor(initialState = {}) {
    this.state = initialState;
    this.channel = new BroadcastChannel('app-state');
    this.listeners = new Set();
    this.channel.addEventListener('message', (event) => {
      this.state = { ...this.state, ...event.data };
      this.notifyListeners();
    });
  }
  setState(updates) {
    this.state = { ...this.state, ...updates };
    this.channel.postMessage(updates);
    this.notifyListeners();
  }
  subscribe(listener) {
    this.listeners.add(listener);
    return () => this.listeners.delete(listener);
  }
  notifyListeners() {
    this.listeners.forEach(listener => listener(this.state));
  }
}
// Usage across different tabs/windows
const appState = new SimpleState({ user: null, theme: 'light' });
appState.subscribe((state) => {
  console.log('State updated:', state);
});
appState.setState({ user: { name: 'John' } });

Result: Cross-tab state synchronization in 30 lines of code, using modern browser APIs that the existing library ignored.

The Art of Strategic Reinvention

The key insight here is the principle: “Reinvent for insight. Reuse for impact”. When you’re learning, exploring, or trying to understand a problem domain deeply, reinvention is invaluable. When you need to ship a product and solve well-understood problems quickly, reuse makes sense. Consider these factors when making your decision: Reinvent When:

  • The existing solutions are overkill for your needs
  • You’re in a learning phase
  • Performance is critical
  • You need something highly specific to your domain
  • The maintenance burden of the custom solution is acceptable
  • You want to eliminate external dependencies Reuse When:
  • The problem is complex and well-solved by others
  • Security is critical (like authentication systems)
  • Time to market is the primary concern
  • The solution needs to integrate with a larger ecosystem
  • The maintenance burden would be too high

The Team Dynamic Challenge

Let’s address the elephant in the room: your teammates might not appreciate your reinvention enthusiasm. Here’s how to handle the inevitable “Why didn’t you just use Library X?” conversation:

Come Prepared with Data

Show your analysis. Demonstrate the bundle size savings, performance improvements, or maintenance benefits. Make it about the project, not your ego.

Start Small

Don’t rebuild React on your first day. Start with small utilities and prove the value incrementally.

Document Everything

Your custom solution needs better documentation than any third-party library because you’re asking your team to trust you instead of the crowd.

Plan for Knowledge Transfer

Make sure you’re not creating a bus factor problem. Write tests, document decisions, and ensure others can maintain your solution.

The Future-Proofing Argument

Here’s something the “don’t reinvent” crowd often misses: every external dependency is a potential future problem. Libraries get abandoned, maintainers burn out, licenses change, and breaking changes happen at the worst possible times. When you control the solution, you control the timeline. You can fix bugs immediately, add features as needed, and never worry about waiting for someone else’s roadmap to align with your needs.

Conclusion: Embrace Selective Rebellion

The “don’t reinvent the wheel” advice isn’t wrong – it’s incomplete. The complete version should be: “Don’t reinvent the wheel unless you have a good reason, understand the trade-offs, and are prepared to maintain your solution.” Sometimes the wheel needs to be reinvented. Maybe it needs to be lighter, faster, or shaped differently for your specific use case. Maybe you need to understand how wheels work to build better vehicles. Or maybe you just need a wheel that doesn’t come with 47 other wheels you’ll never use. The next time someone tells you not to reinvent the wheel, ask them this: “Are you sure this wheel is actually round?” Your users – and your bundle analyzer – might thank you for questioning the orthodoxy. Just remember to bring data to the code review, because you’re going to need it. What’s your take on this? Have you ever built something custom that worked better than the popular alternative? Or have you been burned by reinvention attempts? Let’s discuss in the comments – I promise I won’t suggest you build your own comment system.