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By Gary Butler 4 min read



🚩 Introduction

In today’s software development world, third-party libraries are like trusty sidekicks. They make life easier, whether it’s handling form validation, date manipulation, or even building out full UI frameworks. They’re a go-to for saving time and effort in the short term. But here’s the catch — relying on them isn’t without its risks. Remember the NPM left-pad incident? It’s a perfect reminder that we need to think twice before pulling in external dependencies and consider how they might affect our projects in the long run.



💥 The NPM Incident: A Wake-Up Call

In 2016, the JavaScript community experienced an event that brought attention to the risks of relying on third-party dependencies. The NPM package left-pad; a simple 11-line piece of code that padded strings with leading zeros; was removed by its maintainer. Despite its simplicity, left-pad was a core dependency for many other packages, some of which were used by large applications and frameworks.

When left-pad was removed from the NPM registry, it caused build failures across many projects that depended on it. This issue highlighted the potential challenges of relying on third-party libraries, especially when they are critical to the functionality of larger systems.

The incident reminded us of the risks of relying on external code that we don’t control. While third-party libraries can speed up development in the short term, they can create long-term issues if they are not properly maintained. This event highlighted the importance of being cautious when adding dependencies to our projects, as they may cause unexpected problems later



🧩 Key Lessons Learned

1️⃣ Dependencies Can Break Your Project

One of the most significant lessons from the left-pad incident was how fragile the dependency ecosystem can be. A small package, with minimal code and functionality, can bring an entire project to a halt if it is removed or altered unexpectedly.

While many developers were able to recover quickly by either finding an alternative or reimplementing the package themselves, the incident exposed the risks associated with relying on code from external sources that we don’t control. When a third-party package goes offline, becomes deprecated, or is simply poorly maintained, your project is at the mercy of the open-source community’s choices.



2️⃣ Unnecessary Dependencies = Project Bloat

The NPM incident highlighted the bloat third-party dependencies can bring to a project. Even a small utility like left-pad can become a fragile point of failure in a dependency-heavy codebase.

Adding a third-party package means introducing not just its code but also its dependencies. This can quickly lead to versioning conflicts, larger project sizes, and slower build times.

Over time, managing these dependencies becomes a burden. You’ll need to monitor updates, apply security patches, and address compatibility issues, complicating project maintenance.

“That tiny helper might pull in a hundred other modules behind the scenes.”



3️⃣ Security Risks Lurk in Hidden Corners

Third-party libraries can pose security risks. In 2018, NPM reported that over half of open-source vulnerabilities stem from dependencies. The left-pad incident, though not a security breach, exposed the ecosystem’s fragility.

Many packages are maintained by volunteers and may lack strict security practices. Neglected or outdated libraries can introduce vulnerabilities, such as insecure dependency versions, putting your application at risk.

Relying on poorly maintained packages increases the chance of exploits, highlighting the importance of evaluating and managing dependencies carefully.



4️⃣ Maintenance: Out of Your Hands

Third-party libraries come with the risk of losing control over their maintenance. Many are managed by small volunteer teams, so if maintainers abandon a project or stop updating it, the library may become incompatible with your code or frameworks.

Moreover, the project’s development may not align with your needs. Updates could introduce breaking changes or alter functionality unexpectedly. Relying on external developers for maintenance highlights a key drawback of third-party dependencies.

“When a library’s direction and your app’s needs diverge – you lose control.”



5️⃣ Trust Comes at a Price

The left-pad incident underscored the importance of trust in external code. NPM’s vast library ecosystem makes it tempting to assume packages are safe, well-maintained, and bug-free. Yet, popularity or high download counts don’t guarantee quality or security.

Third-party libraries can introduce unexpected side effects or behaviors, especially if they aren’t thoroughly vetted or if their authors follow different coding standards. Worse, malicious actors can disguise harmful code in seemingly harmless packages, posing a significant risk to your application.

“Just because it’s on NPM doesn’t mean it’s safe.”



🛡️ How To Minimize Risk (and Still Ship Quickly!)

While third-party libraries have their place in modern development, here are some strategies to minimize the risks associated with their use:

  • 💡 Evaluate Necessity: Before introducing a third-party library, ask whether the feature or functionality can be implemented within your application. Simple tasks like string manipulation, date formatting, or array filtering might not require an entire library.
  • 🔎 Audit & Monitor: Regularly review your project’s dependencies and ensure they are actively maintained. Tools like npm audit or dotnet list package --vulnerable can help identify vulnerabilities in your dependencies. Be prepared to refactor your code to remove a dependency when the package is no longer maintained.
  • 🌱 Prefer Lightweight & Actively Maintained Packages: Choose libraries that are lightweight, have a strong community around them, and are actively maintained. Libraries with clear documentation and a transparent development process are usually safer bets.
  • 🔒 Pin Your Versions: Use version control and ensure that you lock down the versions of your dependencies. This will prevent unexpected breaking changes from introducing instability into your project.
  • 🏗️ Build In-House When Practical: Whenever possible, develop your own solution to maintain full control over the code, updates, and maintenance. Only rely on third-party libraries when creating an in-house option isn’t commercially viable or practical.



🎯 Conclusion

The left-pad incident highlighted how third-party dependencies can streamline development in the short term but pose significant risks to long-term application stability. While these libraries can save time and effort, they also bring potential for disruptions, security vulnerabilities, and ongoing maintenance challenges.

To balance immediate gains with future reliability, developers must thoughtfully evaluate their dependencies. By minimizing unnecessary libraries, practicing vigilant dependency management, and prioritizing resilience, you can enjoy the short-term benefits of faster development without compromising your application’s long-term health.