Facebook programming language launched

January 25, 2013

Social networking site Facebook has launched an in-house programming language to fight spammers. According to Software engineer Louis Brandy, the Feature eXtraction Language is a fast, flexible and safe means for Facebook site integrity engineers to write rules to identify spams before they hits users. Recent research indicated that Spam threats to Facebook’s site integrity change on a daily and even on hourly basis. Attackers peddling a scam one day might tempt users with false promises of various gift certificates the next. However that will come to an end because FXL provides Facebook engineers with the capabilities to keep pace with constantly evolving threats.Louis Brandy said in his blog post that they crafted FXL to expressively codify the business logic of fighting spam and to fetch data as efficiently as possible. Despite the simplicity of the language, it is ruthlessly efficient at fetching large amounts of data from many sources, a task from which the FXL name is derived.

The language was described as a narrowly optimized implementation of a well-chosen subset of Standard ML with customized syntax that sought to optimize FXL rather than require an expansion of the language. The rules expressed in FXL sought out malicious URLs by tapping a users’ link sharing history and data held by URL reputation services and they were coherent in terms of business logic, but poor expressions of data fetching logic. Such a problem was common to large computing systems but was solved with FXL which would automate batching the data fetches in a single network round trip. A conventional implementation would evaluate this code top to bottom, left to right. Facebook engineers would fetch data sequentially, conducting an excessive number of network round trips between the machine executing FXL and the reputation service.

Read more: https://www.facebook.com/notes/facebook-engineering/fighting-spam-with-pure-functions/10151254986618920

Contador Harrison