An article has just been posted on the Twitter Inc. blog about the evolution of the Twitter architecture, infrastructure and technology.. For your convenience here is an exerpt ..

"...We hit some scaling stumbling blocks a few months back, but not because Ruby or Rails was working against us. Once Twitter reached a certain amount of traffic we were forced to rethink our architecture; you don't build a messaging system the same way you build a content management system. We set about developing custom solutions both inside and outside our Rails application. We also made good use of web scaling standbys: caching, database optimization, more hardware, and shared experience. Throughout this scramble to scale, Ruby and Rails were assets for their speed of development and creative, helpful communities.

For stressed engineers, it's tempting to think that another solution - anything but what you're using now! - will solve all your problems. Maybe you start dreaming up the perfect framework on a whiteboard, or maybe you start scouring the web for the fastest, newest, most experimental technology. In the long run, picking a foundation you're comfortable with and making sensible iterations towards your performance goals will yield a bigger win. You have to be careful while iterating: watch your database, test thoroughly, and be ready to roll back when things break (and they will)..."

Go here to read the full article. .

Twitter Inc. has launched a mobile version of their Twitter service. It presumably is meant for mobile devices to be able to access the twitter service directly through the web interface without any 3rd party client needed. We briefly checked it out and it looks to be a pared down version of Twitter formatted for mobile phones.  Here are some screenshots of the new service (taken from a Mac on Firefox 2). 

Twitter Mobile - Login screen 

Twitter Mobile - Logged in and sending messages

Twitter mobile is available at m.twitter.com  

Here is a nice interview with Alex Payne, one of the developers of Twitter. Josh Kenzer asks him five questions about the technology and also a couple of more general questions on Twitter the service. A worthy read, Check it out.

With the exponential growth of twitter in just a few months, there has been some talk that Twitter and Ruby on Rails may not be able to scale. There are some posts today that say that is not the case. Anyway, I am sure that the guys at Obvious and Twitter will FIND a way to make it scale. Every new user and page-view on their hockey-stick-like usage graphs is like cash in the bank. Ok, more like a loan or a promissary note maybe. The point is that they will find the technical solution and the cash to do it, whatever it takes. More users and popularity has got to be adding to their valuation by the month, week, day and even hour. The 64,000 dollar question remains however. Will they sell out our keep growing it into a revenue producing business?

Oh, and if you are interested in those posts, they are here and a more technically minded one here .

The guys over at loud thinking post about a conversation that they had with some of the Twitter developers and the issues around scaling and using Ruby on Rails... Interesting for sure (if you are interested in Ruby or software development).

Interesting to note that at one point along the way, (can't be determined when from the post), they were getting 11,000 requests per second on 16 CPU cores with no caching. I wonder what it is now?