[1] a = { name : "test" }; b = { name : "test" }; what will be a === b ? a===b ? // --->false Object references are not same [2] Explain Login mechanism of site . Asked about how authentic API calls are made when session is active. [3] Question about Data structure . I was told to decrease complexity of particular problem. [4] How backbone views , say BV1 , BV2 , BV3 can message each other ( i.e. event trigger ) Ans : Visit link :http://stackoverflow.com/questions/21977945/backbone-event-bus-multiple- views-on-the-same-page. [5] There are 2 images on single page. Either you want both to be loaded or neither of them. Ans : use sprites [6] Questions related to closure. [7] What is promise in js ? [8] obj = { val : 123 , vals : { val : 45 , vals : { val : 90 } } , name : 'abc' , names : { name : 'xyz'}} make it : obj = { val : 123 , vals_val : 45 , vals_vals_val : 90 , name : 'abc' , names_name : 'xyz'} Ans : Use recursion . There can be better solution. [9] Asked about projects [10] which is faster call or apply Ans : call is faster . You will get answer from stackoverflow. [11] How you inherit properties in js prototypes . [12] what is target and currentTarget [13] Difference between .bind() , .on() , .live() . delegate() functions . backbone events : {} uses which one of the above ? [14] CSS positioning related questions . what is box-model (I didn't know) [15] asked about reactJS [16] requireJS and routing in backbone. [17] Their favorite question : How browser works ? [18] puzzle : 5 points (x,y) pair in XY plane . All (x,y) of 5 points are ONLY integers. Prove that at least one pair will have midpoint which is going to be integer (x,y). ( Pigeon hole concept ) 100 doors puzzle . [19] How browser links classes with actual DOM . What is BOM and DOM. [20] difference between cache and local storage Prepare well on backbone (routing , events , requireJS ) / angular / nodeJS . Prototypes , constructors , closure , CSS . They ask if you have something your own online to show them . Have look at some internals of the basics like how browser works , how data is linked . If you are good at basics , housing is not that tough .