I applied to that university online and after a few months I got emails from professor who are interested in my background. Usually professors will keep in touch through emails for a short period to select candidates. Then we scheduled a interview over the phone. The professor talked a lot on his own research as well as his team. He also asked me to briefly introduce my background on academic research. After that, he sent me several papers and set up a second phone call to to further evaluate my potentials based on my understanding of their papers. Not that difficult, but a fast progress to final decision making step.