The Tech Guru Behind Worldcoin: a Q&A With Tiago Sada

The head of product for Tools for Humanity grew up in Mexico, became an expert in robotics and won a scholarship to study in the U.S. Now he's overseeing one of the most interesting (and controversial) blockchain projects.

AccessTimeIconOct 11, 2023 at 4:05 p.m. UTC
Updated Oct 11, 2023 at 5:13 p.m. UTC
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Worldcoin, the crypto project created by OpenAI’s Sam Altman, has garnered a lot of media attention for its use of "proof-of-personhood" and for using its Stanley Kubrick-esque orbs to scan user’s irises.

The user authentication system has prompted many blockchain experts to voice concerns over how it protects privacy of those who choose to use the blockchain.

Tiago Sada, head of product, engineering and design at Tools for Humanity, which is developing Worldcoin, said he initially was skeptical to join the crypto space, and still believes that many of the projects in the industry are scams.

But what sold him on blockchain was Ethereum: "You were able to digitalize things that you could not digitalize before," he told CoinDesk. He’s now on a mission to spread the gospel of the importance of identity and decentralization with proof-of-personhood.

We spoke to Sada a few weeks ago, and asked him questions about Worldcoin and other blockchain topics. Some highlights include:

  • Sada’s personal story for how he got into blockchain and crypto
  • Sada’s take on Vitalik Buterin’s criticism of proof-of-personhood
  • The connection between AI and Worldcoin


Did you have much blockchain experience when you were recruited for this job?


​​So I actually hated crypto when I was building my startup. I thought it was just all a scam, to be honest. And part of my job as a fintech founder, I had to be very good at explaining why it made sense to build the fintech rather than on the crypto route. But after we sold that, and I took a year off just to explore, live in the desert, and a bunch of other stuff, I had a chance to really think about where the future was going and just give crypto another chance.

And to be honest with you, I still think 80% of crypto is not really going to pan out. But there's 20% of it that I think is incredibly profound and incredibly important.

In particular, for me, Ethereum was what really clicked. Just the way you were able to digitize things that you could not digitize before.

And the composability, having gone the route of building a product in the old legacy world, and now just getting to build things in a weekend that you couldn't do before; it's really really crazy.

So that was before I joined the project. I started playing quite a bit in the crypto space, building a couple of interesting projects.


I thought it was interesting how you mentioned you were coming at this from the direction of thinking crypto is a scam, I think you're probably in good company in the Y Combinator world.

And I just wondered first, broadly, whether in the tech community that you are a part of, have you found sentiment toward crypto broadly becoming more positive or less positive In the past six months?


I think they've definitely gotten much better in the last six months.

Last year FTX was definitely a low point for the ecosystem. The bull cycle before that was definitely really good for just getting a ton of talent into the space. And I think that what you've seen in the year since FTX is, a lot of the noise has gone away.

The people that didn't believe in this space, they have just gone to explore something else. And so the people that are sticking it out, that are still working on things, are the people that tend to be working on the most interesting stuff because they're in it for the right reasons.


You also mentioned how you're kind of skeptical, broadly from a use case perspective. You said that around 80% of these things are probably going to disappear and I don't think you'll find many people, even in crypto disagreeing with you.

But you're building a platform that is going to be incumbent on there being use cases in the future. And Ethereum, you mentioned, that's also a platform, but it's not itself a use case. So I wonder without being too prescriptive, and just spinning up dapps and programs yourself, what kinds of use cases do you expect to really see take off on Worldcoin or using WorldID as an authentication method?


Yeah, I would actually push back on that. Worldcoin and WorldID are built on top of blockchains, and specifically uses Ethereum because that is the best way to build that is the best tech, technological primitive – if you want to build something like this that is decentralized, if you want to build in a way in which you can be a public good, if you want to build it in a way in which it's like fully privacy-preserving.

Most of the integrations actually of World ID, they're just Web2 companies, the same with our users.

We've done one thing where we take a bit of a different approach, is we don't think you should have to understand what a 12-word seed phrase is and what all of these complex primitives are. We think they're super important, and we leverage a lot of those for WorldApp and for World ID, but most of our developers and our users are not crypto developers are not crypto users. They're just people. They're just using an app because they want to send money, or you're signing into a website.

For example, one of our most popular integrations is with Discord. People are just using the World App to sign into Discord. And yes behind the scenes we’re settling with zero knowledge proofs on-chain and that's very, very important, but users and developers don't really get to know that.

So I don't think we are betting on crypto or DeFi as a space replacing or upgrading the current world. But we're really betting on just the need for proof of personhood and identity in the world. Whether that is on mobile apps, whether it is on the Web2, or of course, smart contracts and Web3 applications.


You brought up proof of personhood, and I read Vitalik Buterin’s comments on his concerns over proof of personhood. I wanted to hear your take on his concerns.


I think Vitalik’s take is great. We got a chance to discuss a lot with him before he posted that.

I was very surprised that some people took it as feedback on Worldcoin. I would say it's basically by validating most of the hypotheses: and when he says, ‘It should work for decentralization on the project,’ that's something that is being actively worked on. I don't think you will meet anyone that would disagree with that.

I send Vitalik’s blog to people all the time. I think he does a really good job explaining why this is such an important problem, and why there's not too many options other than an approach, basically like what Worldcoin is. It's also not a perfect approach, It has some trade-offs, and he does a good job of laying those out.

We're working with a bunch of people in the community to help solve or mitigate those.


What is the connection between AI and proof-of-personhood?


AI is an incredible new tool for humanity. It's like inventing fire.

But inventing fire requires you to have new tools to be able to handle that fire.

Proof of personhood is something that is already important on the internet today. Right? That's why we've had things like captchas. That's why we have things like KYC and all these different things. But the problem becomes both much more important, and much more difficult.

All those existing solutions, they stop working in the day where we need them the most. And I think that from Sam's perspective, he knew he just could see that someone was going to crack this.

And so it was just very important that a system like Worldcoin was built in a way that is decentralized, in a way that is privacy preserving.

If you talk to most people, it’s not even a question of whether a system like this will exist or not. The only question is whether it will be decentralized, whether it'll be open source, whether it'll be privacy-preserving.


I'm sure it was frustrating to see how you all were painted after your launch. I know you guys have taken a lot of pains with the privacy-preserving encryption steps to kind of differentiate what you're actually building from the way that you're being depicted as these people just stealing eyeballs.

Where do you think that that misunderstanding comes from and do you have a game plan to actually explain to people, ‘We don't actually do anything with this data’?


I think there's a difference between some very loud Twitter users and just the reality on the ground. One of the first things that we had to test obviously back when the project started was are people excited, or concerned, or skeptical about this? How do they feel about the orb?

And part of the reason why we went to so many places in the early phases was just understanding and hearing people.

It turns out that the average person understands this very well, they're used to biometrics being used in not a privacy-preserving way. Most of these people have face ID on their phones. They use some sort of biometric to authenticate when they get to work, they go through immigration like anyone that gets a visa is used to just giving away all of our biometrics.

So when you hear about a system that does this in a private way, and is much less intrusive, people are usually quite excited about signing up.

So I would just say that the attitude can be very different. And at the same time, I think it's super healthy for them to be skeptical. I think that we are doing something that is definitely and very important for the world and people's privacy.

We've been burned for the past 10 years by big companies doing not so good things for our privacy, so I think people should be skeptical.

Part of why that project has worked and part of why you sometimes see a hater on Twitter and then six months later, they're talking about how great Worldcoin is, it’s because when people understand what is actually happening, they're usually very excited about what the system is.

It's very unintuitive, because they're amongst the most private systems at this scale that have ever been built. And so it takes time with any type of new technology.

Right now we are, frankly, just catching up to meet the demands of early adopters. And so we'll worry a lot more about like later adopters by the time we can get to them.

Edited by Bradley Keoun.


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Margaux Nijkerk

Margaux Nijkerk reports on the Ethereum protocol and L2s. A graduate of Johns Hopkins and Emory universities, she has a masters in International Affairs & Economics. She holds a small amount of ETH and other altcoins.

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