5 Question Interview with Twitter Developer Alex Payne

I reached out to one of the developers on the Twitter team and asked if he would answer 5 questions. Alex not only answered them but is very honest and up front with his answers. Thanks Alex!

1. How did you end up on the Twitter team? What is a little of your background?Pretty simple: they posted on their blog that they were looking for
   people in late 2006, and I jumped on it! I think I replied within a
   few hours of the posting. I starting doing contract work on Twitter
   earlier this year, and earlier this month I accepted a full-time job
   after working in the Obvious office for a week. I’m moving out to
   San Francisco in mid-April, and I can’t wait to be out there with the
   rest of the team.I’ve lived most of my life in the Washington, DC area. As one might
   guess, being in the nation’s capital means that everything revolves
   around politics. Most of my early jobs were developing web
   applications for various non-profits, non-governmental organizations,
   and for-profits supporting campaigns and such. I’ve also done some
   information security work (an equally ubiquitous industry around DC).I came to Rails after working in PHP like many developers, but I’ve
   never been a language purist. I was looking at developing some Ruby-
   based blogging software with a friend a couple years before Rails was
   on the scene, but at that time it just wasn’t a friendly language for
   web endeavors. When Rails first crossed my eyes I remember thinking,
   “cool, someone made Ruby work for web apps!” I jumped right in to
   working with the early releases.
2. How has Ruby on Rails been holding up to the increased load?By various metrics Twitter is the biggest Rails site on the net right
   now. Running on Rails has forced us to deal with scaling issues -
   issues that any growing site eventually contends with – far sooner
   than I think we would on another framework.The common wisdom in the Rails community at this time is that scaling
   Rails is a matter of cost: just throw more CPUs at it. The problem
   is that more instances of Rails (running as part of a Mongrel
   cluster, in our case) means more requests to your database. At this
   point in time there’s no facility in Rails to talk to more than one
   database at a time. The solutions to this are caching the hell out
   of everything and setting up multiple read-only slave databases,
   neither of which are quick fixes to implement. So it’s not just
   cost, it’s time, and time is that much more precious when people can['t]
   reach your site.None of these scaling approaches are as fun and easy as developing
   for Rails. All the convenience methods and syntactical sugar that
   makes Rails such a pleasure for coders ends up being absolutely
   punishing, performance-wise. Once you hit a certain threshold of
   traffic, either you need to strip out all the costly neat stuff that
   Rails does for you (RJS, ActiveRecord, ActiveSupport, etc.) or move
   the slow parts of your application out of Rails, or both.It’s also worth mentioning that there shouldn’t be doubt in anybody’s
   mind at this point that Ruby itself is slow. It’s great that people
   are hard at work on faster implementations of the language, but right
   now, it’s tough. If you’re looking to deploy a big web application
   and you’re language-agnostic, realize that the same operation in Ruby
   will take less time in Python. All of us working on Twitter are big
   Ruby fans, but I think it’s worth being frank that this isn’t one of
   those relativistic language issues. Ruby is slow.
3. How difficult has it been to add hardware to the environment?We’re hosted at Joyent, and they make the “throw more CPUs at it”
   approach easy. We’ve been able to get new server containers
   provisioned within hours, generally.I’d like to experiment with Amazon EC2 to handle load spikes, but the
   prospective database latency is prohibitive.
4. How large is the current Twitter road map? How many features are you guys looking to add?Not to be evasive, but it’s hard to say right now. There’s a lot
   that we’d like to do while still maintaining a simple, focused, easy-
   to-use service. Lots of people are interested in a groups feature,
   and that’s definitely on our radar. There’s lots of good stuff coming!
5. How do you see Twitter affecting the blogosphere, IM, SMS, and Email?I don’t think Twitter is a replacement for blogging, just as I don’t
   think blogging is a replacement for journalism. As far as
   communicating ideas to an audience, one-to-many, Twitter works best
   for those particular ideas that are terse yet expressive, and don’t
   benefit greatly from an in-place thread of replies. For more
   personal (some might say mundane) updates, I think Twitter is a
   better fit than a blog. People are going to talk about their cats,
   inevitably, but do you really want someone talking about their cat in
   more than 140 characters?I think the real power of Twitter is its ability to channel over
   different mediums at the user’s whim. IM, SMS, email, and the web
   are just transports as far as Twitter is concerned. Generally, you
   have to go out and get information via whatever medium that
   information is on. With Twitter, information can come to you via
   whatever medium you prefer. Or, if you want some space, you can
   easily turn off the information tap with a simple “off” command.
   That’s powerful.