Yahoo's Recruitment

System Engineer / Backend Engineer

Preferred Qualifications:

* Solid object-oriented programming experience
* Strong analytical/problem-solving skills
* Proficiency in programming and data management
* Proficiency in C/C++ or Java

* Proficiency in Perl/Python/shell script
* Strong coding and debugging skills
* Experience in system designing and architecting
* Proficiency in UNIX/Linux tools and utilities
* Good communication skills, good in written and oral English

* B.S./M.S./Ph.D in computer sciences or related fields

Optional qualifications:

* Natural language processing, machine learning, information retrieval, data mining

* Experience in large scale Internet applications

* Experience in online advertising, search technology,
* Experience in database, distributed computing, online serving system
* 2+ years of industry experience

I viewed the recruit, and then I got the conclusion. The popular programming languages are C/C++, Java, Python and so on. Additionaly, you must love the open source and agree the spirit of hack culture.