Hyejin is an associate professor at Seoul National University and an external faculty at the Complexity Science Hub and the Santa Fe Institute.

Before Seoul National University, she was an associate professor of Kellogg School of Management at Northwestern University and Northwestern Institute on Complex Systems (NICO), and a research fellow at Harvard Kennedy School, and at MIT Media Lab, and a senior research fellow at Mathematical Institute at University of Oxford , and Institute for New Economic Thinking at the Oxford Martin School. She acknowledges National Science Foundation (USA): 1) Rule of Life; 2) the Structure of Technology; 3) Technological Change from the Map of Capabilities. Her PhD is in Statistical Physics at KAIST. Hyejin serves on Associate Editor at PLOS One and Management Science.

Her research aims to develop a mathematical and computational framework to understand complex systems.