I start all of my talks at conferences on architecture and scaling with describing the distinct differences between scaling and performance. I define scaling in one word: specialization. I, somewhat jokingly, retort to the question of what performance is with “Who cares?”.

The reason for not caring (much) about actual performance is that whether or not you use single quotes, double quotes, objects, functions, Python, Ruby, PHP, foreach, etc. has nothing to do with whether or not your application and site will scale.

Scaling is entirely about IO. Fundamentally, it’s about whether your data is being stored in a manner that makes retrieving it at the rate of today’s high traffic websites possible. In other words, Ruby isn’t the reason you can’t store 250,000,000 records in MySQL and do range scans. It’s because MySQL (and most RDBMS’s) suck.

I’ve been playing with Django a lot lately for a side project. Despite being a pragmatic coder to a fault, I’ve decided to truly learn another language and I felt Django would ease the shock a bit. So far I love it. Django’s patterns make a lot of sense and I’m loving the goodies a true OO language like Python gives me. Since starting down this path I’ve been getting two questions over and over:

1. Does this mean Digg is going to be using Django?
2. Why didn’t you choose Ruby on Rails?

Digg will not be using Django or any other framework anytime soon. We deal with traffic that most Django developers will probably never see. Our stack receives billions of requests a month. That kind of traffic, as I stated earlier, requires specialization. Django is the exact opposite of this. It’s a generic web framework made to answer the majority of web programmer’s basic needs. The majority of web programmers don’t deal with the problems we deal with. I’m sure if you ripped out a lot of what makes Django so great (e.g. the models, admin, etc.) Django would be fine (e.g. If we used it only for mapping requests to views and templates), but then it wouldn’t really be Django would it?

I chose Python and Django over Ruby and Ruby on Rails for a number of reasons. First and foremost is that we use Python here at Digg. Learning Python will only enhance my ability to perform my duties at Digg. I, personally, dislike the Perlisms in Ruby. Additionally, Ruby seems to skew towards implicitness in the language, while Python skews toward explicitness. I like explicitness.

To sum things up, I have nothing technically against Ruby as a language, I love frameworks for regular development work and Perl’s syntax kills small children.

Choose what you love and be happy coders.