Like anyone aiming to build great Web systems, we’re concerned with the performance of the systems we build. We want to craft experiences that feel fast and responsive. I’ve even trumpetted the performance of this very site.

On the Web, ‘performance’ tends to refer to fast server response times, optimized assets for fast downloads, and generally limiting size and complexity of code that needs to be transferred to and executed on client devices.

Instead of this focus on performance, we’re better served by focusing on efficiency.

The term ‘performance’ brings to mind exotic super-cars suitable only for impractical demonstrations (or ‘performances’). ‘Efficiency’ brings to mind an electric car (or even better, a bicycle), making effective use of limited resources.

Computing power is the most obvious resource at play in the world of Web and mobile app development. The time and attention of those using our systems are also a resource that should be treated with respect.

Much like an electric car can be a better driving experience than an internal-combustion vehicle, an efficient Web system feels lighter and faster. It uses less power on the server and the client device (including your precious laptop and phone battery).

To push the automotive metaphor even further, efficiently designed Web and app systems can also have a real impact on carbon output. After all, we’re working on bicycles for the mind, not SUVs.