The first interview was by phone call, High level questions ( what do you know about the company, did you worked with such technologies ? .... )
The second contact I was aked to deliver a peace of my work ( source code, diagram ,...) by email
The third interview was on site, the questions were about logic & mathematics, to solve on a white board
and at the end I was asked to write a java code " 100% correct" to solve a problem like : in this Question I asked if the numbers are distincts, they said yes, I wrote the code accordingly ( While loop ), but when i finished, they corrected the source code to replace "while" by "for" loop to support the duplicated elements !