Design Principle: Minimize Dependencies

When I started building the base framework for Looping, I defined a set of design principles to guide its development. Establishing these principles from the start helped refine my thinking, avoid implementations that felt "off," and encourage simplicity, abstraction, and reusability for long-term maintainability.

One of those core principles is Minimize Dependencies—a principle that has shaped many of my decisions in Looping’s architecture. External dependencies introduce invisible complexity and long-term maintenance burdens, so being intentional about when and why to take them on is critical. In this post, I’ll break down how I apply this principle and the trade-offs involved.

Invisible Complexity

The urge to reach for a gem or package when you're under pressure or just excited to deliver a feature can be high—especially when you've always been told not to "reinvent the wheel." For example, user authentication is table stakes in most apps, but when you add Devise to your Rails app, you don’t just add a single line of code to your Gemfile—you introduce tens of thousands of lines plus another five nested dependencies into your app. Meanwhile, Looping’s auth system is just a few hundred lines, tailored specifically to its needs without unnecessary overhead.

I'm not trying to pick on Devise. Almost everyone who has written a Rails app has heard of it. It’s been around for a long time and is widely used, with more than 225 million downloads according to RubyGems.org. But that’s exactly the issue. A widely used gem that adds an enormous amount of invisible complexity to your application is something you need to be deeply aware of. Just because a library is popular doesn’t mean it’s worth adding to your app.

The Burden of Maintenance

If you’re serious about building something that lasts, the fewer dependencies you take on, the less time you’ll need to spend upgrading them in the future. The less time spent maintaining dependencies, the more time you’ll have to focus on what differentiates your app from competitors.

Conventional wisdom says to ship as early as possible—just get it out there. Naturally, that means you don’t "reinvent the wheel" and instead reach for existing libraries to get to what makes your app special as quickly as possible. But in doing so, you're leveraging your future for the present. Your app’s fate is now tied to every one of its dependencies. The time investment may seem negligible at first, but if what you’ve built lasts, every dependency will require ongoing updates. Some may break in the future, while others may become abandoned and incompatible with newer framework or language versions. Over time, the long-term cost of maintaining dependencies can far exceed the initial time investment of building certain features yourself.

This is especially true for side projects. If you start something as a side project, your primary investment is your time. There may come a point when your app generates some revenue, but not enough to justify full-time work on it. Instead, you may want to maintain it periodically while focusing on something new. When that time comes, would you rather spend your limited hours improving your app or upgrading dozens of dependencies?

Reduced Flexibility

Another overlooked downside of relying on external libraries is reduced flexibility. A library may solve 90% of your problem but introduce unnecessary complexity or force trade-offs that don’t fit your specific needs. Workarounds can pile up, and in some cases, modifying the library itself may be necessary—negating the original benefit of using it in the first place. When you own the implementation, you have complete control over its behavior, making it easier to tailor to your application's requirements and evolve it as your needs change.

Being Intentional

None of this means you should avoid dependencies entirely. There are cases where pulling in a well-maintained library is the right decision. But the key is being intentional. Consider:

• What problem does this dependency solve?
• How much invisible complexity does it introduce into my application?
• What is the long-term maintenance cost?
• Will it limit my ability to customize or extend functionality?
• Could I build a simpler version myself in a reasonable amount of time?

Minimizing dependencies isn’t about stubbornly avoiding external code—it’s about ensuring that every dependency you take on is worth the trade-offs. By doing so, you set yourself up for long-term sustainability, reduce complexity, and maintain greater control over your application's future.