14 DAY TRIAL // By now, most Facebook users should have gotten the Timeline profile feature. As with any big changes on Facebook, the feature is not without its critics, but it's hard to underestimate the scope and scale of the project which is to help you highlight the important events of your life on a single page.
Being one of the most used Facebook features, a site used by half a billion people each day, you can imagine that it was a rather massive project and a lot of effort was put into making sure it works for everyone and doesn't cripple the Facebook infrastructure while doing so.
"Timeline isn’t just a bold new look for Facebook—it’s also the product of a remarkably ambitious engineering effort. While our earlier profile pages surfaced a few days or weeks of activity, from the onset we knew that with Timeline we had to think in terms of years and even decades," Facebook explained.
"At a high level we needed to scan, aggregate, and rank posts, shares, photos and check-ins to surface the most significant events over years of Facebook activity," it said.
But, as most things at Facebook, Timeline started out at a hackaton event with a team of four people which put together a working demo in one night.
That was in late 2010, after that Facebook got to work designing a system that scaled.
It relied on proven technologies at the site, MySQL/InnoDB for storage and replication, Multifeed for ranking entries, that's the same technology that's behind the News Feed ranking, Thrift for communication and memcached for data caching.
All of these have been in use at Facebook and the company already had the tools to manage and debug them. In a new note on its Engineering page, Facebook goes into detail on how it built Timeline and how it works.
It's a worthwhile read for anyone interested in doing work on this scale or just for anyone interested in how a big site like Facebook handles things.