1. mvc and other design patterns and implementation details; pros and cons of approaches taken. traversal of arrays, optimization, O-analysis, lists (search, removal), trees (search, traversal, removal, deletion), hashmaps; you will be well prepared if you study "Programming Interviews Exposed" and "Cracking the Coding Interview". All questions are designed to see if you are fundamentally sound. 2. web app optimization and debugging; scenarios, challenges, approach / resolution, rendering time, basics of http, javascript internals, single threaded model, etc. All are questions designed to see if your skills and experience match what they need to hire for. 3. behavioral, personality, cultural fit, challenges, achievements, motivation, interests; All are questions designed to see if you are going to work well with the people there.