I possibly cannot give any advice , i am a novice with just two years of experience . But yeah i my interview process consisted of written tests for c & english and math. After that it was one on one with a senior architect where upon learning i was from biotechnology background he didn't probe much into OO principles and actual coding tests .He just asked about my other skills and was impressed by my hardware/OS knowledge .Finally he said you seem to learn quickly so that's all is required.

Two years & two accounts later i have worked on j2ee,spring & struts framework,perl,shell scripting,sharepoint,web developement,frond-end UI.Still trying to learn :)