CS50 Hackathon

The CS50 Hackathon is an epic all-nighter in the HBS Hives atop the i-lab in Batten Hall at 125 Western Avenue during which you can dive into your final project’s implementation alongside classmates and staff. If you choose to partake, you’ll be asked to propose three milestones for yourself that evening: a “good” one that you intend to achieve no matter what; a “better” one that you think you can achieve; and a “best” one that you hope to achieve. Felipe’s will be served around 9pm; Domino’s will be served around 1am; and those still awake at 5am will be treated to breakfast at IHOP. Snacks and drinks will be served throughout the evening. Gluten-free, vegan, and vegetarian options will also be available.

When to get there

Harvard Students

So that check-in isn’t overwhelmed (and you aren’t stuck waiting in line!), do arrive at the HBS Hives per the times below (unless you need to arrive later, in which case just arrive asap). If you can’t make your prescribed time or if you want to travel with your partner(s), that’s fine!

If your LAST name starts with… arrive at HBS Hives at…
A – G 7:00pm
H – N 7:15pm
O – Z 7:30pm

Yale Students

So that we arrive in time for Hackathon’s start, please meet outside Arthur K. Watson at 51 Prospect Street by 3:30pm on Tue 12/3, unless you’re on the late shuttle at 5:15pm. You will be asked to fill out a brief waiver form before boarding the charter buses, which are scheduled for a prompt departure. Buses should have outlets and Wi-Fi, though best to charge all gear and download all files ahead of time, just in case. In addition, food will not be served until 9pm or so at the Hackathon, so best to order a bag lunch or bring other snacks with you for the ride. Finally, a reminder that if you take a bus to Harvard with us, you must return to Yale with us.

How to get there

Harvard Students

  • If walking from, say, Out of Town News, follow this route. Odds are the walk will take 20+ minutes.
  • If taking the shuttle, take the Allston Express to the i-lab (which is where the HBS Hives are), per the schedule for the Allston Campus Express PM; consult the column called i Lab Western Ave. Those are regularly scheduled shuttles, not CS50 Shuttles, so space will be limited. Odds are the trip will take 10+ minutes.
  • If driving, drive to 125 Western Avenue in Allston (aka Boston). Metered parking is available behind the i-lab, in the lot whose entrance is on Western Avenue itself.

If you find yourself lost, text 6177122750 or email heads@cs50.harvard.edu and tell us what you see around you!

Yale Students

See When to get there.

What to bring

You must bring…

  • Harvard ID or Yale ID (unless you don’t have one, in which case bring a printout of the CS50 Bot’s confirmation of your spot)
  • Laptop (that supports Wi-Fi) plus power adapter

You might also want to bring…

  • Blanket; pillow
  • Camera
  • Contact lens case/solution; eyeglasses
  • Headphones
  • Phone with charger
  • Sweater/sweatshirt
  • Water bottle

You may not bring…

  • Alcohol, etc.


To see announcements and chat with classmates during the Hackathon, visit cs50.ly/slack. (If you can’t seem to sign up, email heads@cs50.harvard.edu.) If prompted, enabled “desktop notifications.”

To create a new channel, click ⊕ to the right of Channels at top-left.

To get someone’s attention in a chat room, type @ and then their name (assuming they’ve logged in too).

Announcements will be posted to #general, and you can also join these channels!


Can I attend?

Space is limited, so attendance may be lotteried. If you registered for a spot at this year’s Hackathon, you should have heard from the CS50 Bot as to whether you have a spot! If not, email heads@cs50.harvard.edu to inquire.

Can I arrive late?

Yes, you may!

Can I leave early?

If you really, really want to, yes. If you leave before 3am, call the Evening Van Service at 617-495-0400 before 2:30am to arrange for pick-up. If you leave between 3am and 5am, best to use Lyft or Uber or call 617-782-5500 for a taxi. If leaving on foot, be sure to walk with multiple friends.

Can I go to IHOP?

Space at IHOP is even more limited than the Hackathon itself, so attendance at breakfast may be lotteried separately, depending on how many classmates are still awake at 5am!

Please forgive if we can’t accommodate everyone who’d like to go!

How do I check in upon arrival?

First visit the check-in tables in the ground-floor lobby. Then complete your check-in at cs50.ly/checkin.

What if I can’t attend after all?

If the CS50 Bot confirmed your spot but you can no longer attend, please email heads@cs50.harvard.edu right away so that we can give your spot to someone who’s waitlisted.

What if my partner was waitlisted but I wasn’t?

Let heads@cs50.harvard.edu know.

What music was played?

Coming soon!

When does it end?

By 5am for folks who’re sleepy and by 7am for folks who’re awake (and hungry!) for IHOP, though attendance at breakfast may be lotteried.

When does it start?

Around 7pm, but do check when to get there.

Will there be food and drinks?

Yes! With so many folks in attendance, though, do try to be gentle with quantities.

Will there be gluten-free food?

Some, yes. It’ll be set aside, so just check with the staff as to where it is.

Will there be shuttles?

Harvard Students

If, because of mobility impairment or medical condition, you find it difficult or impossible to use Harvard’s shuttles, do contact the Evening Van Service in advance of the Hackathon to make arrangements to and from the Hackathon. Just let heads@cs50.harvard.edu know if you need a hand.

To the Hackathon?

Yes, via regularly scheduled shuttles. But space will be limited, so it’s probably best to walk to the Hackathon instead with friends.

With that said, you can take the Allston Express to the i-lab (which is where the HBS Hives are), per the schedule for the Allston Campus Express PM; consult the column called i Lab Western Ave. Those are regularly scheduled shuttles, not CS50 Shuttles, so space will be limited. Odds are the trip will take 10+ minutes.

From the Hackathon?

Yes, via chartered CS50 Shuttles. Some of the shuttles will head to IHOP around 5am, depending on how many classmates are (still!) hungry, and some shuttles will head to the River houses, Yard, and Quad.

With that said, space will still be limited, even though we’ve literally reserved every shuttle that Harvard owns! So the shuttles destined for the River houses, Yard, and Quad might make multiple loops, in which case there might be a bit of a wait. But you’re welcome to walk home with friends if you’d rather not wait!

Please forgive, especially if weary or grumpy at that hour, if we can’t quite fit everyone into shuttles all at once!

Yale Students

To the Hackathon?

Yes, see when to get there.

From the Hackathon?

Yes, via the charter buses on which you arrived. On Wed 12/4 morning, one of two buses will depart for IHOP, where a bountiful breakfast will be served, after which it’ll return to Yale, arriving around 10am; the other bus will head straight to Yale, arriving earlier.

Will there be office hours?

The CS50 Hackathon is as much about bringing everyone together at term’s end as it is about removing the last of the course’s training wheels. As such, while some of the course’s staff will be on hand to answer questions via Ed, they’ll also be working on projects of their own! (I.e., the Hackathon isn’t designed to be 12 hours of office hours. :) Odds are you’ll also know more about your project than us, so we’ll do our best to help, but do plan to lean on classmates and Google too!

Will there be vegetarian food?

Yes! There will be vegetarian options from Felipe’s and Domino’s in addition to fruit and veggies.

Will there be Wi-Fi?

Yes. But best to download anything big (e.g., software, movies, etc.) beforehand, lest Wi-Fi at HBS be a bit slow with so many people on it!