This Is CS50.

CS50 is exceptional for its size, its resources and the cult of personality around its charismatic leader. It is more than just a class at Harvard; it is a cultural touchstone, a lifestyle, a spectacle. This is CS50, and it’s here to stay.
Mohammed N. Oosman, a university recruiter for Facebook, welcomes the crowd at CS50 Puzzle Day. Malan has described "a mutually beneficial relationship" between CS50 and tech companies.By Madeline R. Lear
By Cordelia F Mendez

UPDATED: September 18, 2014, at 12:33 a.m.

Half a dozen production assistants, all clad in black, scurry about the stage in the seven minutes between the end of Economics 10 and the start of Computer Science 50. Towering over the commotion and dressed simply in his signature black sweater and jeans is David J. Malan ’99, who tests his mic and toys with the many contraptions on stage. He has spent over 24 hours preparing to deliver this introductory lecture. Students file in.

The stage in Sanders Theatre is flanked by the statues of former Harvard President Josiah Quincy and early patriot leader James Otis. The two stare imposingly at Malan on the 59-ft. wide stage, and out into an auditorium that can seat over a thousand.

“This. Is. CS50,” Malan proclaims, pausing between each word.

This is the phrase he has said since he began teaching the class in the fall of 2007.

video clip of YouTube CEO Susan D. Wojcicki ’90 promises that the class will be engaging and important even for students of the humanities like herself, a history and literature concentrator who took the class as a senior, around the same time that Malan was in middle school and most computers were still in black and white.

“CS50 changed my life,” she claims to an eager audience of shoppers ready to believe it.
Over the next 53 minutes, no bell or whistle is spared in making computer science seem approachable and fun. A steel apparatus topped with lightbulbs, built by Ansel B. Duff ’15 and Dan B. Bradley ’14 over the summer, demonstrates the concept of a byte. Immediately rewarded, two students who operate it correctly are gifted with colorful lights for their rooms. In a trademark gag, Malan rips apart a phone book to show how binary search works.

If CS50 were a carnival, Malan would be its charismatic ringleader, seamlessly moving from trick to trick.

Now it’s time for the finale. In a sweeping denouement, Malan introduces LaunchPad, a music mixing device, which will be operated by course “Technologist” Colton Ogden, a slight but muscled EDM geek who wears many hats on Malan’s staff. Ogden graduated from Saddleback College in Mission Viejo, Calif. with a degree in computer science and describes himself on Twitter as a “Budding programmer/game developer, writer, gamer, musician, and person.”

The lights dim until Sanders’ Stage is pitch black. Hundreds of MacBook screens glow in the audience. A video of swirling colorful lights plays behind Ogden. Ogden, whose pale skin shimmers over the light of the controller, begins to play an original adaptation of a techno song, but no sound fills the cavernous theater.

“Quick fix, quick fix!” Malan snaps repeatedly at the production team. This hadn’t happened in the tech run-through in August.

By Connie Yan

“Quick fix, quick fix!” Aides scurry from inside the tech booth to fix the issue (a loose cord). Malan is forced to uncharacteristically pause and cede control to a question-and-answer session with the audience. There is laughter, perhaps because it is absurd that something usually so seamless has been derailed. Malan jokes about editing the technical difficulty out in post-production before the video is disseminated on the internet. Quickly fixed, Ogden is back in business while booming music closes the show, and cake will follow for all shoppers.

Three days later, minutes before the start of CS50’s annual Puzzle Day, Malan admits disappointment at the botched ending.

“I died,” Malan says. “I would have much rather gone out on a perfectly smooth note.”

Perfectionist is a word that describes Malan to a T. Having taken over the course with a middling enrollment in the low hundreds, in the past eight years Malan has brought it to a peak, with record-breaking attendance and a new energy among students for learning computer science. Despite having seemingly perfected the model for the class, each year brings new gadgets, inventions, and gimmicks.

This year’s lights and music spectacle of 889 strong (not counting the teaching staff) couldn’t feel further from private tutorials in the Barker Center or clunky lectures in dusty Sever. CS50 is exceptional for its size, its resources and the cult of personality around its charismatic leader. It is more than just a class at Harvard; it is a cultural touchstone, a lifestyle, a spectacle. This is CS50, and it’s here to stay.


This fall, 12 percent of the College is enrolled in CS50, and cutting edge technology, like 3D printers and cameras filming in 4k resolution, fills the classroom and course offices—a cushy complex at 125 Mt. Auburn Street that shares a building with the Division of Continuing Education and HarvardX.

To understand CS50 as it is today, it is important to know how much it has changed. Since the introduction of the course in 1989, attendance has varied, with enrollment in most semesters in the ’90s hovering around 200.

A revolving door of faculty members have taught the class, from current Faculty of Arts and Sciences Dean Michael D. Smith to Henry H. Leitner, associate dean of DCE. Both men have played a significant role in the development of Malan’s career. Smith served as the adviser to his doctoral thesis (“Rapid Detection of Botnets through Collaborative Networks of Peers”) and Malan has called Leitner his mentor. Malan said that every request he’s had of Leitner, be it “financial, or a blessing to try something new,” has been answered with a “yes.”

When Malan himself took the course in the fall of 1996, it was taught by current Princeton computer science professor Brian W. Kernighan.

Kernighan, who at the time worked as a researcher at the Bell Laboratories in Murray Hill, N.J., had never taught a course larger than a small seminar—quite a different experience from teaching the 300-odd students that enrolled along with Malan that semester.

“I volunteered to [teach] not quite realizing what I was getting into,” Kernighan says. “I’ve never worked so hard in my life as I did that semester.”

Kernighan never came to know Malan as a student. Malan was, in his own words, “one of these incredibly uptight Harvard students.” He began his time at the College set on a rigid, planned path towards concentrating in government. Able to take the class because Kernighan would allow him to enroll Pass-Fail, Malan began his education in computer science and immediately loved it. He even looked forward, he admitted, to spending Friday nights working on the newly released problem sets.

“I almost missed out, and thankfully the professor that year and the course that year was so incredibly alluring that I did it, and I stayed,” Malan says. “That was a very special thing.”

And thus, Malan’s own path was irrevocably altered by CS50. He switched his concentration to computer science, graduating with a 3.9 GPA in the field. His first Harvard teaching job came as a lecturer in the Extension School while a he was a senior at the College. After year-long stints teaching high school math and working at a wireless startup, he returned to Cambridge for his master’s and doctoral degrees.

He hasn’t left Harvard since, and now serves as the Gordon McKay Professor of the Practice of Computer Science. While Malan does not do a significant amount of research and thus is not on the tenure track, his position is one with a five-year contract that can be renewed indefinitely.

In the fall of 2006, a year before the start of Malan’s reign, the course enrolled just 132 students under the tutelage of Smith, mostly CS concentrators. In 2007, Malan’s first year, attendance more than doubled to 282 students. The numbers have since risen steadily to a course-record 889 enrollees this fall, including cross registered non-College students.

So what is it that has made this class, once a backwater for video gamers and coding addicts, the class with the highest enrollment in the College in five years? What causes hundreds to pull near-weekly all nighters? What is CS50?


When peppy tour guides litter the Yard, coaxing high schoolers to apply to Harvard, they extol the virtues and wide availability of intimate seminars with tenured professors. When harried Harvard students search for courses to take, many often look for “gems” with as little work as possible to free up crammed schedules.

With a workload rating averaging a solid 4.0 on the Q Guide, and a difficulty at nearly that mark, CS50 is far from a cakewalk. And yet hundreds—78 percent of whom claim to have no prior computer science experience—file in twice a week for Malan’s electrifying lectures. Many more tune in from home for the open courseware version at while more than 150,000 registered for the first iteration of CS50x in 2012-2013.

With four producers, a manager, a handful of student photographers, and dozens of teaching fellows and course assistants, CS50 is no modest production. One would be hard pressed to think of another class in the College with its own staff of videographers and a full production team. No history class takes students to lunch at Fire + Ice weekly, as CS50 does each Friday. There’s no live feed of one of N. Gregory Mankiw’s rare Ec 10 lectures.

The course has a staff that can number more than 100. This year, the corps of teaching fellows and course assistants is led by Gabriel L. Guimaraes ’17, a Brazilian-born sophomore who translated CS50 into Portuguese while in high school to teach in his home country. He became a TF during his freshman fall.

A table full of Facebook paraphernalia rests next to another filled with snacks at CS50 Puzzle Day on September 6, 2014. The Facebook-sponsored event included a photobooth and electronic giveaways.
A table full of Facebook paraphernalia rests next to another filled with snacks at CS50 Puzzle Day on September 6, 2014. The Facebook-sponsored event included a photobooth and electronic giveaways. By Madeline R. Lear

Robert T. Bowden ’13 is one of the most visible members of Malan’s team. He is an affable recent grad who speaks with a careful and bright timbre not unlike Malan’s. For CS50, he has served as teaching fellow, assistant head teaching fellow, head teaching fellow, preceptor, and is now listed as a “Member of Technical Staff” as he completes his first year of a doctoral program in computer science at Harvard.

The course had a large impact on Bowden’s college experience. “CS50 and TF-ing in general was my big extracurricular,” Bowden asserts. “What I spent my time on outside of courses was mostly CS50. ... Some of my best friends in college and continuing on now were through CS50.”

This year, some of those 818 College students taking CS50 may never even step foot in Sanders Theatre. A recent policy change by the Administrative Board restricted simultaneous enrollment in overlapping courses, even those with videotaped lectures, yet granted an automatic dispensation for CS50.

Bowden notes that with lectures only making up a fraction of one’s time in CS50, physical attendance may no longer be necessary. “The course has gotten to a point where we have so many resources and ... it’s no longer the case that the live experience, being in Sanders Theatre, being lectured to, is superior to even sections as separate things, office hours Monday through Thursday, the videos that are online, the shorts that are online [and the] message boards that we have,” Bowden says.

Another supplement to lectures are CS50’s many events. Two weeks ago, with study cards yet to be printed and signed, recruiting was out in full force at Puzzle Day, a day of problem-solving, pizza, and prizes early in the semester designed to excite Harvard students about the class. Facebook frisbees and playing cards filled the tables and Mohammed Oosman, a New York-based university recruiter with the Zuckerberg empire, was present to open the ceremony, which Facebook has sponsored four years in a row.

A rubik's snake rests on a table at CS50 Puzzle Day on September 6, 2014. The Facebook-sponsored event featured Facebook and CS50 paraphenalia and giveaways.
A rubik's snake rests on a table at CS50 Puzzle Day on September 6, 2014. The Facebook-sponsored event featured Facebook and CS50 paraphenalia and giveaways. By Madeline R. Lear

With dwindling resources in the humanities and a constant worry about the constraints of the FAS budget, it may seem troubling that CS50 comes across as a bit of a spendthrift. But while the School of Engineering and Applied Science, FAS, and DCE may foot the bill for many of the course’s expenses, over a dozen tech corporations also kindly chip in.

“Over the years I sort of realized that I could reach out to our friends at Facebook and Google and college friends of mine who were in tech companies,” Malan says. “There’s a mutually beneficial relationship there, whereby we would love some support to make this course tradition possible and this undergraduate experience possible. They would love to chat up undergrads and talk about recruiting opportunities.”

A list of sponsors ranges from Amazon to Canon to Microsoft to Facebook, companies that pay for the food at events like Puzzle Day and the Hackathon, with the hopes of perhaps recruiting course alumni or teaching staff to work in the industry.

In response to a request for comment by Smith, FAS spokesperson Colin Manning wrote that Harvard will work alongside “corporations, foundations, and the government” to provide funding for “ pursue their own academic research interests and to advance the learning of our students.” Neither Manning nor Smith provided a comment to directly address the case of CS50.

There is an implication in the branding of CS50 that the class is the first step toward future employability for students, a fact highlighted by the ease of applying to work for the course immediately after completing it. There is even a perceived pipeline to a career in Silicon Valley.

And the exceptional nature of CS50 extends even further. A final note on “Academic Honesty” in the course syllabus states, “If you commit some act that is not reasonable but bring it to the attention of the course’s heads within 72 hours, the course may impose local sanctions that may include an unsatisfactory or failing grade for work submitted, but the course will not refer the matter to the Administrative Board.” Effectively, the Ad Board can be avoided by any student who admits to breaching their academic integrity within three days of committing the act. In the past, up to 5 percent of enrolled students have been involved in Ad Board cases regarding the class, according to a recent CS50 lecture.

Guidelines from the College-wide “Harvard Plagiarism Policy" state, “Students who, for whatever reason, submit work either not their own or without clear attribution to its sources will be subject to disciplinary action, up to and including requirement to withdraw from the College.” There is no mention of a 72-hour window for reporting cheating. Neither Malan nor Brett Flehinger, interim secretary of the Ad Board, responded to requests for comment on this policy.


For some students, and most staff, CS50 is not just a course but a lifestyle and community. The class’ appropriation of Harvard jock culture makes it tough to walk through campus without running into a DHA-inspired “Property of CS50” t-shirt, just one example of the endless giveaways, swag, and paraphernalia the course makes available.

Slices of cake await the rush of students after the first CS50 lecture.
Slices of cake await the rush of students after the first CS50 lecture. By Connie Yan

While many students form close bonds with members of clubs, athletic teams or social organizations, devoted CS50 TFs and CAs say they have found a niche within Harvard inside the walls of Maxwell Dworkin or the CS50 Research and Development Offices on Mt. Auburn Street.

“I would say there’s definitely a quirky sense of humor that the course has tried to maintain,” Malan says. “We’ve increasingly been trying to instill a sense of community and culture even within the CS50 staff alone, and this comes in the form of having staff-only T-shirts and sweatshirts and things that really make you feel part of this intimate community.”

Bowden, whose twin brother Paul was also a CS50 TF, serves as a freshman proctor on the first floor of Thayer Hall. With an air of a boyish charm and often clad in his CS50 course gear, he looks like he could be a student in the class rather than one of its longest tenured staff members. He describes CS50 as continuingly integral to his social experience at Harvard.

“It was sort of a thing that I would go somewhere and people would be like, ‘He’s the CS50 head TF,” Bowden says. “From a social aspect, it was definitely a large factor in my undergraduate and even now graduate life. People talk to my freshmen; I heard someone walking by and be like, ‘You have Rob Bowden as a proctor? Oh my god, he’s the CS50 guy.’”

Jason C. Hirschhorn ’14-’15, a former teaching fellow whose sections are available on the web as part of CS50x, also says that his CS50 involvement has led to a degree of celebrity.

“Many students around the world know my name,” Hirschhorn says. “I don’t think they know many personal details about me…[but] I’ve told personal anecdotes in my sections which I’m happy for students to hear, like funny personal anecdotes to break it up and make it more personalized.”

And at the center of the fame that comes with the course is Malan himself, who boasts 15,760 followers on Facebook yet still finds the time to respond to the dozens of comments he receives from legions of fans. With the way his course has traveled to all ends of the globe, Malan sees CS50 as a portal for reaching more people and connecting them together.

“We have some 30,000 subscribers [to our Facebook group], who have been part of this group now for many months, and it’s fascinating to see people from the U.S., from India, from France, from literally all over the world, crossing paths because they’re sharing in this mutual experience,” Malan says.

But the stardom and spectacle certainly aren’t limited to the celebritized teaching staff and the class’s internet presence; it’s at the core of the course itself. In fact, it’s difficult to cite a CS50 event that doesn’t involve a sensory overload with mountains of food, flashing lights, and blasting Top 40 music.
This festive rigmarole has made the course a viral must-see for incoming Harvard students, who stream into Puzzle Day as early as half an hour before the event starts.

A CS50 staff photographer photographs a puzzle piece at CS50 Puzzle Day at the iLab on September 6, 2014.
A CS50 staff photographer photographs a puzzle piece at CS50 Puzzle Day at the iLab on September 6, 2014. By Madeline R. Lear

Groups of four and five students pose for photos with a range of props from oversized sunglasses to plush speech bubbles, beneath their own images projected on a massive scale to the curving white wall above. Facebook posters and banners adorn the cavernous space, and a pair of sophomore TFs in cut-up purple CS50 Puzzle Day T-shirts stand at the top of the stairs to welcome the throng like party motivators.

Armed with candy and puzzle booklets created by Facebook, the entrants quietly gather in group clusters and get to work. They are excited by the possibility of prizes, but also to begin to hone their problem-solving skills.

A group of four freshmen—three of whom planned on taking CS50 this semester—describe the class as famous. They’ve heard about it from their upperclassmen friends.

“It’s like a legend,” Jessica M. Wang ’18 says of CS50. “Puzzles sound fun and there’s also free stuff involved if you’re good enough. ... It seems like an experience, you get to go through the Hackathon, you get to go to the fair—it’s a lifestyle.”

Even old school administrators echo, in a more formal sense, the general sentiment that drives the droves of students to slave over problem set after problem set, even stay up all night eating Chinese food while coding.

“We are evangelical about our subject,” says former Dean of the College Harry R. Lewis ’68, currently the director of undergraduate studies for computer science. “We want to compete for students. We want to take all the students who thought they couldn’t do computer science. We want them to understand that it’s going to going to be hard and fun. .... We’ve been doing the shenanigans for years.”


If one were to arrive at the Harvard Innovation Lab roughly 90 minutes before the kickoff of Puzzle Day, one would find David Malan perched behind the check-in table, fussing with production staff over how the shade of purple on this year’s t-shirt will appear on print-outs from the event’s photo booth. A hallmark of the class and its culture are the countless numbers of Facebook albums posted by Malan and course staff of every CS50 event, many of which have a photobooth-esque area with plentiful props. Even the lighting of these photos is under Malan’s scrutiny.

Despite the hundreds that will pour into the “hives” of the i-Lab over the course of the day, CS50 remains a very “high touch” experience, to quote Lewis. All of this is made possible through the time, energy, and sheer control that Malan exerts over the class.

After a mandatory two-day workshop for staff before the start of classes this semester, at which all participants become CPR and First Aid certified (Malan has been a trained EMT since 2003) and complete various skill-building workshops, Malan sent course staff multiple firm emails (copies of which were obtained by Fifteen Minutes) saying, “if ever contacted by the press for a quote or interview about CS50...please confer with me via email or phone beforehand” and “if caught off-guard by a reporter in person or by phone, just decline to comment at the time and offer to follow up once we’ve touched base.”

Despite a jocund manner on screen, Malan is nothing but serious about the image of the course. For his staff, this comes across through his high expectations.

“All TFs in CS50 would agree with this: that CS50 is probably more work than other courses...because there is such a high expectation of quality and [Malan] expects that out of his TFs,” Bowden says. “He has very big visions for getting things done that are hard to meet, but with everyone trying to put in the effort you can kind of get there.”

Even students not employed by Malan have described the high bar he sets for work and the demanding way his expectations materialize. Bill, a student at the College, has taken CS50 and has contributed ideas to Malan for the course. Bill was granted anonymity by Fifteen Minutes because he is working alongside Malan and fears his employment prospects would be negatively affected if his name is used.

According to Bill, who characterizes Malan as self-promotional, his grading policies were often opaque and had little rhyme or reason. Bill said that when Malan was evaluating a group project, he did not look at the content of their code, but rather based grades on the short presentations of their projects.

“To be fair [Malan has] built up CS50 from almost nothing,” Bill says. “It’s become a cornerstone of the department, and I think that the way that he makes computer science accessible and seem enjoyable—and it is enjoyable—is credit to him. ... If there were ever a cult, it’s CS50.”

Malan attributes much of his success with undergraduate education at Harvard to his background as a former student, with the ability to identify with and understand the teenagers populating his current classroom.

Photobooth pictures feature CS50 teaching fellows at Puzzle Day on September 6, 2014. Some TFs have felt a degree of celebrity working for the high-profile course.
Photobooth pictures feature CS50 teaching fellows at Puzzle Day on September 6, 2014. Some TFs have felt a degree of celebrity working for the high-profile course. By Madeline R. Lear

“I have a very personal vested interest in [Harvard] because it’s so impacted me,” Malan says. “It’s defined my life in the past few years, and I daresay CS50 has become my life in recent years.”


For all that Malan scrutinizes each minute aspect of events like Puzzle Day, his actual presence during the event is surprisingly light. Despite the amount of micromanaging before the event—the shade of purple on the photos, a request that TFs not hang and dangle from the pipes below the ceiling, the arrangement of giveaways on tables—he takes a backseat role as soon as students begin to arrive.

Relegated to a position behind the check-in table, Malan greets students as they arrive and monitors the staffers. Still, when it comes time for formal remarks, he lets Belinda L. Zeng ’17 and the duo from Facebook welcome the crowd, exalt the learning of computer science, praise CS50, and explain the schedule of the day. He does not even rise to join the speakers at the top the stairs and instead stands several feet back from the eager masses, observing the program that he’s built.

This is not to imply any degree of negligence on his part. Malan does not shy away from the microphone, though he has spent copious amounts of time working on his public speaking abilities. As an undergrad at the College, Malan was an unsuccessful UC presidential candidate—which he still reflects on nearly 20 years later and partly blames on “how badly [he] performed” in a public debate.
This day has been choreographed and coded. Every move comes with forethought, both for this semester’s course and more broadly for the class’s future.

“We are hopeful that we will make some sort of dent in the model for higher education, which is a bit grand, admittedly, since we’re just one course in computer science no less,” says Malan ambitiously when questioned about his longer term goals for the course.

After spending several hours at Puzzle Day and answering my many questions, Malan’s still eager to sell me the class. He pauses to personally thank me and my multimedia partner for coming and reminds us to take a t-shirt as we leave the hives.

CollegeScrutinyStudent LifeFASComputer ScienceTechnologyFront FeatureHighlightFM Front FeatureMike Smith