Howdy Android Developer interview questions

It was a really cold first interview. They asked me some normal interview questions as how I see myself as a person and to say my level in a bunch of technologies. I felt I could not really talk so much to make the interview to get to know me better. They say one of their benefits is full transparency about their business model but they don't even say the payment range for the position. I had to analyze an pseudo-code and give the output of the function and also say the Big O notation for the function. I got a really general feedback without any reason why I didn't get through the process.