The most common focus area for Software Developer Intern position in any big silicon valley company are Data Structure, Algorithms, Complexity, System Design, Multi-Threading.  The best preparation materials:-List of useful books Most important book- "Cracking the codding Interview"    Cracking the Coding Interview: 150 Programming Questions and Solutions: Gayle         Laakmann McDowell: 9780984782802: Amazon.com: Books Programming...