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Joe Leo

A Closer Look

A bit about me

Joe brings his mix of engineering muscle, business acumen, enthusiasm for challenges, and technical leadership to the helm of Def Method. Before founding DM, Joe spent over a decade as a developer delivering high-quality software solutions spanning government, education, finance and e-commerce.

As the CEO and Founder of Def Method he emulates the brand values of transparency in business operations, trust among the team and partners, and excellence in code.

Joe is co-author of The Well-Grounded Rubyist, Third Edition. Outside of the office, he has helped to build the NYC developer community as lead organizer of GORUCO, a member of the Technical Advisory Board of the New York Founding, and an instructor at General Assembly.

When did you know that you wanted to be a developer?

"I knew I wanted to be a software engineer at about the same time I wrapped up my graduate degree - in cinema studies.

At that point I was 'technical,' building some very basic software for NYU School of Medicine. I loved film, which I studied at night, but my day job was getting more and more interesting.

Finally, I decided that I could always fall back on my degree and pursue film in some form. So why not give this software thing a real shot?

The rest is history."

Projects & Roles

Case Management System for Human Services

Lead a team to meet SOW feature requirements and refactored Javascript to pay down technical debt and allow faster new feature delivery.

Mobile Wallet Software

Developed mobile payment processing tools, administrative portals, custom analytics processes, and APIs for web and mobile application.


Home Town

New York, NY

Current Town

New York, NY


BS, Engineering, Penn State and MA Arts, NYU

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Languages & Technologies

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