I knew this question might be more technical, but amazing to know at least some background information about hosting model and how a dynamic site with millions of users can be navigated very fast...

Also, with slow Internet Line, I can always navigate SO without any problem :)

Can you please explain how you made that?

  • Thanks @MartijnPieters: but we also knew about them, what is amazing here how these system integrated that makes the site very fast :) – user210003 Jul 23 '13 at 12:11
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    Caching...the answers is always caching. – Bart Jul 23 '13 at 12:12
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    (lots of server power) + (efficient coding) + (minified resources) + (tons of caching) = what you see. :) – Shadow Wizard Wearing Mask Jul 23 '13 at 12:13
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    Google's indexing has nothing to do with SO itself. It's just that the site is popular and frequently "updated", so Google pays attention. – Bart Jul 23 '13 at 12:16
  • I thought about caching, but each page and post has variables such as votes, comments, status update! then I think its a power of juqery somehow and ajax – user210003 Jul 23 '13 at 12:16
  • @phwd: why you deleted the image? – user210003 Jul 23 '13 at 12:26
  • @Bart: I will be wrong, but fast indexing by google indicating a connection between SO and Google :) I love to see became partner – user210003 Jul 23 '13 at 12:29
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    There is no connection between Google and Stack Exchange. Google's algorithm just loves sites that are frequently updated with lots of new content. That's what we do. – Cody Gray Jul 23 '13 at 12:37

We are fanatical about performance - everything boils down to that. Every day we look for ways to improve.

  • Can we not run a query here?
  • Can we consolidate queries?
  • Can we extend this index to cover 20% more cases?
  • Can we denormalize this data to eliminate a join?
  • Can we stick this in redis?
  • Should we stick this in redis?
  • Should we aggregate this into a central DB?
  • Can we eliminate this API call?
  • Is JSON right here?
  • How about Protobuf?
  • Can we not do an allocation here?
  • Can we completely change how this is cached and accessed?
  • Is this hit often enough to rewrite it in IL?
  • How about we just replace the ORM?

...these are daily questions around here. It's a culture thing, and we love it.

Edit: I am preparing an architecture overview for our upcoming Velocity talk in October, we'll be sure to share it when done - for those that are curious.

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  • That what I expected, there is no linear system for fast performance, the hardware and integration plays a part in performance, but optimization is also great when the site viewed by millions of user :) – user210003 Jul 23 '13 at 12:31
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    We control all the hardware and software - so how we setup the network bonds, tweak the TCP buffers, layout security so low-latency queries need not pass a router, etc...it all plays a part, it just adds up. I should write a post on everything we do in the name of performance (it's a long, long list), just have to find the time. – Nick Craver Jul 23 '13 at 12:33
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    Don't forget Unicorn dust. It really speeds things up. – Oded Jul 23 '13 at 12:35