Mindy Park is a satellite communications engineer who works for NASA in SatCom. She once joked about being "Space Paparazzi" or an "Interplanetary Voyeur".
She monitors the satellites that are pointed at Mars and sends out emails as imagery becomes available. She has a master's degree in mechanical engineering which she often thinks is wasted at her current job. She works the 3 AM shift which she finds very dull and constantly drinks coffee to keep herself awake.
She was the first one to realise that Mark Watney was alive after seeing that the rover had moved from where Commander Lewis had said it was in her logs. She immediately found the contact details for and then called Kapoor as he was the Director of the Mars Mission.
It became her responsibility to redirect all the available satellites (12 NASA and 2 ESA) onto the ARES 3 site. She learnt Morse code so that she could read messages from Watney quickly without having to look up each letter and even changed her sleep pattern to match his driving times when Mark made his way to the Ares IV site.
Despite arguments otherwise, Andy Weir has not issued clear-cut descriptions of most/all of the characters. People have taken her nonexistent Korean-ness as a fact and so this caused quite a controversy amongst Asians as Venkat Kapoor was also un-asianafied. This is why it's not whitewashing/racist.