If you aggregate jobs from other sources then be prepared for absolutely awful data quality. Firstly, recruiters don't understand their specialism ( http://news.ycombinator.com/item?id=112521 ). I've lost count of adverts for "open sauce" developers and suchlike. Secondly, they brazenly lie about details. If a job is advertised with a salary between x and x*3 then the latter is very theorectical. This type of practice is encouraged because it rises to the top when you trivially aggregate.