2. Jane Street Capital: Founded in the year 2000 by three traders and a technologist, Jane Street Capital takes the second position in the list of toughest companies for job interviews. The quantitative proprietary trading organization operates around the clock and around the globe by understanding the world’s highly competitive financial markets. Jane Street Capital boasts of hiring applicants through the tough interview procedures and training them by giving them the tools they need to innovate. The company has its offices in New York, London, and Hong Kong.