As CS50 gears up for its second semester at Yale this fall, it will do so with a different face at the helm of the class.

Computer science professor Brian Scassellati, who taught the class last fall, will no longer be the head instructor for CS50. Instead, Patrick Rebeschini, a postdoctoral fellow in the Yale Institute for Network Science, will lead students in what was one of Yale’s most popular classes last semester. Rebeschini, who completed his undergraduate studies in Italy and later pursued both a master’s degree and a Ph.D. at Princeton, was chosen as the lead instructor last Friday, and has since then started to acquaint himself with the class and its staff.

“I am super excited to be able to contribute to this class,” Rebeschini said. “It’s really unexplored territory, and everyone has been very approachable.”

Scassellati said he had always planned to teach CS50 for just one semester, as he has multiple other responsibilities at Yale including running a research group, leading a research project and teaching a robotics course.

While Scassellati said he enjoyed teaching the class, he felt many of his other duties were neglected, and that he missed spending evenings with his children.

“At most universities, large introductory computer science courses are taught by dedicated lecturers who don’t have research or other teaching responsibilities,” Scassellati said on Wednesday. “I hope the CS Department can find someone who is experienced in the classroom and can devote their entire attention to this project.”

Computer Science Department chair Joan Feigenbaum said the department looked for someone with specific characteristics, such as familiarity with large, introductory computer science courses, as well as experience with training and mentoring learning assistants.

Feigenbaum noted that Rebeschini “fits the bill perfectly.”

“CS50 is really two classes in one,” Rebeschini said. “It’s making sure the TAs know how to teach, figuring out the best way to deliver the material to them and from them to the other students. That’s what makes me the most excited.”

During his six years at Princeton, Rebeschini taught as a teaching assistant and served as a head TA. He also had an active role in the McGraw Center for Teaching and Learning, often leading daylong workshops for incoming TAs.

At Yale, Rebeschini does research in statistical machine learning with electrical engineering and statistics professor Sekhar Tatikonda.

Since spring 2015, he has also supervised a group of senior students on research projects in machine learning and is a member of the Yale Postdoctoral Association, a group that works to facilitate and promote teaching experiences for postdocs in the sciences.

Though his work at Yale has thus far focused on machine learning and not on computer science, Rebeschini highlighted the many intersections between the two fields.

“I already collaborate a lot within computer science, and my work is really interdepartmental,” Rebeschini said. “Machine learning in itself combines people with many backgrounds, and I have been moving closer to computer science in my research.”

CS50 is similarly interdisciplinary to machine learning, he said,  as  the course attracts students from a variety of different majors and backgrounds in computer science.

Though Rebeschini had multiple meetings with Feigenbaum and CS50 Course Head Jason Hirschhorn prior to his appointment, his first chance to meet the entire CS50 staff was on Tuesday during a Bulldog Days event, at which all teaching and course assistants were present.

“As far as how I’m feeling, I couldn’t be more excited,” Hirschhorn said. “It’s abundantly clear that Patrick is incredibly excited about and committed to providing as outstanding an experience as possible to Yale students come the fall.”

Since being appointed as the head instructor last Friday, Rebeschini has been “doing his homework” to learn more about the course, he said.

By reading past students’ reviews and going through the course’s material, Rebeschini said, he will try to see what can be reworked next fall to make the CS50 experience even better for students.

“Last year [Scassellati] started from scratch,” Rebeschini said. “He has done a great job, but now there’s institutional memory we can use to grow from.”

Though Rebeschini will continue his research in machine learning, he noted his first priority will be CS50, and only when the course “does not need [his] full attention” will he pursue his research.

Fall-term classes begin on Wednesday, Aug. 31.