Arnold Rozon is our 2022 hackathon Grand Prize winner!  His native iOS application CoSign uses near-field communication(NFC) to distribute eSignature requests and biometrics so people can sign documents with their iPhone Face ID. Check out his full submission。

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The makings of a hackathon winner

Getting his first taste for development while working as a designer, Arnold was fascinated and subsequently taught himself to code in his brother’s Chicago basement in just eight months. From there, he’s worked for big Chicago-based tech companies and San Francisco-based fintech startups.

As Arnold progressed in his development career, he found himself gravitating toward mobile development. “I realized I'd become really bored with traditional web programming, so I started learning Swift and iOS development in my own time.”

Eager to hone his new mobile development skills on real-world projects, Arnold turned to hackathons on Devpost and found the Dropbox Sign API Go Paperless Hackathon.

The experimental path of a winning hackathon eSignature app

Designed and built in under seven days, Arnold’s winning hackathon idea, CoSign, lets people sign documents with biometrics and send signature requests through NFC tags.

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Arnold credits the quality of the documentation and the ease of development as the reason he could create a winning hackathon project so fast. “The Dropbox Sign API has really good GitHub documentation. Anytime I needed a method to get information from Dropbox Sign, it was documented and there was an example in the documentation showing me how to use the method and what you could expect as a response. That saved me so much time as a developer.”

To build the biometric element of CoSign, Arnold combined the Dropbox Sign API with iOS Face ID. “I used in-browser JavaScript to select all elements on the Dropbox Sign Signature request.”

Building the Face ID feature into the app wasn’t as straightforward as it seemed, as a conflict between the Sign API and iOS default authentication methods became a blocking issue.

The iOS default authentication for Google single sign-on was OAuth WebView, and this piece was a requirement for the Face ID functionality. However, OAuth WebView wouldn’t support Arnold injecting the code needed to authenticate the signer with Dropbox Sign. Without being able to authenticate the signers, it was impossible to complete signature requests.

Knowing he couldn’t authenticate with WebView, Arnold looked for alternatives. “I realized you can authenticate with Dropbox via a regular web view. So when I press the signature request in CoSign, it opens up the signature request in a normal web view where I can authenticate with Dropbox, and then I have access to the signature request.”

With his workaround in place, Arnold’s Face ID function was operational.

Then when Arnold saw petitioners collecting signatures outside his local Target, inspiration struck for a way to add even more value to his winning hackathon submission. “I started thinking about all the better ways to share information and signature requests that would be easier for someone who's out and about or might be dealing with a large number of people.”

The solution he landed on was NFC tags. By putting a phone near an NFC tag, people would have an easy and contactless way to share information. And by incorporating the Dropbox Sign API signature request function into the process, people could request signatures and sign documents, like petitions, too.

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What’s next for Arnold?

“I think we are at a crucial juncture when it comes to software. The ideas of the past 10 years have become extremely saturated. There are a lot of new paths that we can take as builders. I'm just trying to put myself at the forefront of whatever is coming next. I've recently been exploring content creation, a little bit of blockchain, and I’m trying to learn more about machine learning.”

Congrats again to Arnold. We can’t wait to see what else you build!