Philip Guo is a professor of Cognitive Science, Design, and Computer Science & Engineering at UC San Diego. His research spans human-computer interaction, data science, programming tools, and online learning. He studies how people learn computer programming and data science, and he builds tools to help people better understand code and data. For instance, he created the Python Tutor visualizer tool (https://pythontutor.com/), which helps people learn Python, JavaScript, C, C++, and Java programming by visualizing code execution step-by-step.