Practice SQL queries, especially the joins, and other such stuff. For Java, just read the SCJP book, I think it will cover all. Do understand iterators. They had a lot of questions that had iterators in them. I didn't even remember many of the methods of iterator classes, so I was in a tough spot during the exam. As for C, read thoroughly from a good books that tells you 100% everything about everything in C. I say read the official C standard, or something that paraphrases it. Practice all those formatting questions, simple tricks and things that would make you go berserk. All because you "didn't know that". Trust me, you won't have problems with logic anymore than you'll have regretting you should have read more of the basics. Like i+++++j, or some cunning struct bit field operations, enums, etc. After reading a good book that details every little thing about everything - from printf function to classes to #define macro statement, read "C Traps and Pitfalls by Andrew Koenig". It's a very good book, the stuff you'd read in it will expand your mind. Little things that we overlook. And that's exactly what these tech interview questions have. Read that book.