Of course, only Enterprise Java scales, and we know this because the word Enterprise is right there in the name. Of course, the only platform you should consider is .NET because it has built in caching and hundreds of thousands of college graduates know it. Of course, you need to use PHP because Facebook is written in PHP and Facebook scales. The fallacy of these arguments should be painfully obvious, yet people are shouting these things as if they were gospel truth.

I’d like to offer here, the scalability manifesto. Please repeat these items aloud to yourself every time you want to say something about language X or framework Y not scaling.

The Scalability Manifesto

1. Scalability means the ability to handle increasing load by increasing resources.
2. Scalability does not mean being ‘fast’.
3. Choice of language does not guarantee scalability.
4. Hardware costs decrease exponentially, developer salaries do not.
5. Only you can make your system scale.

Trading performance for development time is generally not a good idea. It’s likely that by the time your application reaches serious traffic levels (if ever), hardware will cost half of what it did when you started. Now does spending twice as much dev time with a lower level language seem justified? Now this is not always the case, but my bet is if you do the math and realize your team of 4 Ruby hackers is doing what a team of 10 Java programmers used to do, you might conclude that linear performance gains due to language choice are not as relevant as hiring smart people who can get work done quickly, and design scalable systems.

There’s no such thing as a free lunch, and that includes scalability.