buildpurdue vs Purdue's Hacking for Defense: A Course Where Defense Problems Become Startups

Hacking for Defense (H4D) at Purdue is a three-credit course, DSB 49000HD, where teams of 4 to 6 students take a real problem from the U.S. defense community and spend a semester interviewing experts until they know what a workable solution looks like. It has no prerequisites and is open to undergraduate and graduate students from any program. It is a class, not a club: you register for it, you earn credit, and the problems come from outside sponsors, not from you. buildpurdue is the open community around it. Nightshift is free for Purdue students with no application, and the startup intake is for students building their own company. Pick H4D if a defense or national-security problem is what you want to work on; pick buildpurdue if you want to build your own idea beside other students.

Key takeaways

• It is a pilot-stage course with a real result. The first section ran in spring 2026 with 17 students from engineering, business, computer science, and cybersecurity. One of its three teams, Rapid Rotor AI, became a company and was selected for a Defense Innovation Unit (DIU) Commercialization Fellowship.
• The problems are sponsor-defined. Each semester has a list of sponsor problems; we did not find how Purdue matches teams to them. Fall 2026's included missile-defense system repair, battery performance, counter-drone coverage, and autonomous river crossings.
• The workload is interviews. Purdue's description says teams are expected to complete at least 10 stakeholder interviews every week and update a Mission Model Canvas as they learn.
• Your major does not matter. Purdue's course page says no prerequisites apply and "your major does not matter, only your willingness to work hard."
• The company is optional. Purdue Innovates says it will help interested teams with startup formation and commercialization after the course. Nothing requires you to start one.
• buildpurdue is where you bring your own idea. Nightshift is free, open to every Purdue student, and needs no application, pitch, or polished plan.

buildpurdue vs Hacking for Defense at a glance

What you are deciding	buildpurdue	Purdue Hacking for Defense
What it is	An ongoing student community: open Nightshift coworking plus a startup intake for founders.	A three-credit Daniels School course (DSB 49000HD) built on the Lean LaunchPad method.
Where the problem comes from	You.	Sponsors from the defense and intelligence communities supply the problems.
Who can join	Current Purdue students.	Undergraduate and graduate students from any program; no prerequisites.
How you get in	Show up to Nightshift, or tell the team what you are building.	Register for the course by CRN each semester. Class size is limited.
Cost	Nightshift is free.	Three-credit course; we found no separate program fee.
Schedule	Recurring open sessions.	Tuesdays and Thursdays, 10:30 to 11:45 a.m., Mann Hall 153 (Fall 2026).
Main output	Whatever you bring: a product, customers, a plan.	A validated solution presented to the project sponsor, with interview evidence behind it.
Where it can lead	Your own startup, plus the Purdue and Indiana network.	A startup around the sponsor's problem, a defense-sector career, or both.

What Hacking for Defense is

H4D was first developed and taught at Stanford and is a Defense Innovation Unit-sponsored program, per Purdue's Computer Science department. The word "hacking" does not mean cybersecurity; the department's description says it means "hacking through government bureaucracy."

Purdue's version is taught by retired U.S. Air Force colonel Ken Callahan, who also directs Purdue's Defense Civilian Training Corps program, with co-instructors Rich Sikora and Matt Dressler. Sikora is an executive advisor for innovation and entrepreneurship at the Daniels School, and Dressler is the funds manager for the Purdue Innovates Incubator. The Daniels School built it with Purdue Innovates and the Office of Research and recruited the first class across the Colleges of Engineering and Science and Purdue Polytechnic.

How the course works

According to Purdue's own descriptions, a semester looks like this:

1. You get a sponsor problem. Teams of 4 to 6 students work on a challenge from the Department of War, the intelligence community, the State Department, or another agency.
2. You interview people constantly. The Computer Science department describes teams interviewing over 100 subject matter experts in a semester. Purdue Business says at least 10 interviews per team per week is the expectation.
3. You report weekly. Teams brief a small faculty group each week and get feedback. Weekly presentations, blog-style fieldwork reports, and a final public presentation make up most of the grade.
4. You test hypotheses with the Lean LaunchPad method. Teams track what they learn on a Mission Model Canvas. The class is flipped, so structured content is online and class time goes to coaching and feedback.
5. You present to the sponsor at the end. There is also a funded travel opportunity, which, if approved, lets students visit sponsors or attend conferences to interview experts.

The point of the design is that you start with the problem, not a technology. Rapid Rotor AI's team lead described the benefit as making sure the team was "trying to solve the right problem for a group of customers who would need a solution."

Fall 2026's problem statements were:

• Rapid air missile defense system repair
• Safe storage to store and transport alternative fuels
• Building better batteries for demanding environments
• Counter-UAS coverage for forward arming and refueling points
• Autonomous wet gap crossings
• Enhanced telemetry for unmanned systems
• Swarming without strings

What happened to the first class

The inaugural section had 17 students, ranging from freshmen to doctoral candidates, split into three teams.

Rapid Rotor AI took a challenge sponsored by the U.S. Army DEVCOM Army Research Laboratory: how to speed up the development of new rotorcraft and drone designs. The five-member team combined AI with aerospace engineering to generate and evaluate rotor geometries. Its lead, Gregory Sapp, said they ran "over 100 interviews over the course of 16 weeks" and "matured into a formal company." The team presented its findings at the Purdue Military Research Institute symposium in April 2026, and on July 16, 2026 Purdue announced it had been selected for the first Purdue cohort of the DIU Commercialization Fellowship, which offers mentorship, commercialization training, and help entering the defense market.

Purdue's coverage is also useful for what it says about the path. Sapp had already been through the Purdue Innovates Incubator's Summer Sprint, and Dressler called his path "an ecosystem success story" built across several programs.

Co-instructor Sikora said on LinkedIn that one third of the first cohort had already formed LLCs. That is a statement about a class of 17, so it describes one pilot section, not a track record.

What to weigh before choosing it

• The problem is a sponsor's, not yours. If you already have a company idea, H4D is a semester on someone else's problem, so it is not a place to develop your own. Some students will find that clarifying; others will find it a detour.
• It is a real time commitment. Ten interviews a week plus weekly briefings is closer to a part-time job than to a lecture course.
• It points toward defense. Purdue Business says the class is especially attractive to students who want to work for the government or the defense sector, and to veterans. The Rapid Rotor AI path ran through the defense market.
• It is early. The course launched in spring 2026, so there is one finished semester to learn from. We did not find an announced section for spring 2027.
• Seats are limited. Sikora's LinkedIn post said class size would be limited. Fall 2026 registration was still open in August, so check with the instructors before assuming it has room.
• Certificate credit was a request, not a rule. Sikora has asked for the course to count toward the Certificate in Entrepreneurship and Innovation. We have not found confirmation that it does, so ask your advisor before relying on it. Our certificate comparison covers how that credential works.

How buildpurdue fits

H4D gives you a problem, a method, and experts. buildpurdue gives you a place and people.

• Nightshift is a low-pressure coworking night, free for all Purdue students, with no application, pitch, or polished plan. You bring the work, get unstuck beside other builders, and leave with a next move.
• The startup intake at buildpurdue.org/cohort is for Purdue students working on a startup. It asks what the company does and what would help you move forward, and early ideas are welcome.
• Events at buildpurdue.org/events put you in a room with the people who run Purdue's programs, including the Purdue Innovates team that helps deliver H4D.

The two are not exclusive. A student could take H4D in the fall and use Nightshift to keep the resulting company moving, or build their own idea at Nightshift and take H4D to learn customer discovery from real stakeholders. If a team forms around a sponsor problem, Purdue Innovates is the program that says it will help with the next step; see our comparisons of its Accelerator and New Venture Challenge.

Which should you choose?

• Take H4D if you want to work on a defense or national-security problem, you like structured interviewing and weekly accountability, and you are fine working on a problem someone else defined.
• Start with buildpurdue if you have your own idea, are still looking for teammates, or want a free, no-commitment place to build.
• Use both if you want to learn customer discovery in a rigorous setting and also have a project of your own. The Nightshift room does not care what the project is.
• Look elsewhere if you want a program that invests in your company. H4D is a course; it does not itself provide funding. For that, see the Purdue Innovates Accelerator.

FAQ

What is Hacking for Defense at Purdue?

A three-credit course, DSB 49000HD, taught through the Daniels School of Business, in which multidisciplinary student teams work on real problems from the U.S. defense and intelligence communities using the Lean LaunchPad method. It launched in spring 2026.

Do I need a defense or military background?

No. Purdue's course page says there are no prerequisites and that your major does not matter. The Daniels School article says the class is especially attractive to students interested in government or defense careers and to military veterans, but it is open to everyone.

Is it only for business students?

No. The first class had engineering, business, computer science, and cybersecurity students. Purdue describes it as multi-disciplinary and cross-listed with several colleges.

Do I need to start a company?

No. The course asks you to understand and test a solution for a sponsor's problem. Purdue Innovates says it will help interested teams with startup formation, commercialization, and continued development, but that is an option after the course.

When can I take it next?

Fall 2026 is in session, meeting Tuesdays and Thursdays. We did not find a published date for the next section. Ask the instructors through the Daniels School or Purdue Innovates.

Does buildpurdue run anything like it?

No. buildpurdue is an open community, not a course. Nightshift is where students work on their own projects, and the startup intake is how a student tells the team what they are building.

Your next step

If you want a defense problem, check the course page and ask about the next section. If you want to build your own thing, come to the next Nightshift or tell us what you are building through the startup intake. For the wider picture of what is available at Purdue, see our guide to Purdue entrepreneurship clubs and programs.