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In the clip embedded below, News.com's Dan Farber asks Facebook's VP of technical operations Jonathan Heiliger how Facebook manages to keep up with adding 50,000 new users per day. Heilliger responds: "We're adding a lot of infrastructure and we're adding a lot of servers." That much we understood. But then Farber probes further, asking Heilliger "what's the basic architecture for delivering information at low latency?" And Heilliger answered, losing us for good:

Our site is similar to a typical Web three tier architecture. We run a collapsed Web and app tier on the top, which is Apache and PHP, both tremendous open source projects. The mid-tier is memcached, which is an open source in memory, distributed cache. And then the data is persisted and stored in MySQL databases — again, open source technology. Around that we have a number of other applications that we've developed in-house.

We're sure, however, that many of our fine readers will understand all this and might even find it interesting. If so, view the clip below. Then please, when commenting, do that thing where you write in code. It's neat!