Q&A with Gravity’s lead engineer: François Guérin

Shiyao Zhang
Gravity
Published in
5 min readSep 23, 2021

Interview Introduction

In the installment of the XTZ.News “Tezos Dev Series”, Gravity offers a Q&A with our Lead Engineer, François Guérin.

In this Q&A, François shares his insights on the Tezos ecosystem and his experience developing Gravity’s decentralized identity protocol on Tezos.

François, can you start off with a short intro about yourself and your work at Gravity?

I’ve been the Lead Engineer at Gravity for the last two and a half years. After getting a Master’s degree in Math, Computer Science and Cryptography, my first experience with blockchain was as the Blockchain Tech Lead at Aubay France, where I implemented a private blockchain within a compliant document certification application.

Now, I manage the technical team at Gravity, which includes an IT Development Manager and Frontend Developer. At Gravity, we leverage blockchain technology to build trusted digital identities.

Users and small businesses leverage Gravity to safely share their personal data to access services such as financing, humanitarian aid, employment, and government services. International organizations and institutions use Gravity to efficiently collect verifiable data for improved service delivery, interoperability and impact.

As the Lead Developer, a big part of my role is to build Gravity’s decentralized identity protocol and blockchain architecture on Tezos.

I’ve also worked to deploy a decentralized credential repository and have Gravity’s decentralized identity protocol recognized by W3C standards as a W3C decentralized identity verifiable credentials standards implementation, ensuring that our protocol is more scalable, standardized and transparent.

Why are you interested in blockchain?

I like that with blockchain, there’s a direct application of my studies with this intersection of math, cryptography and computer science.

Blockchain is also a technology that’s still somewhat “new” for a lot of people, and it’s constantly evolving. I like that there’s a lot that you can learn from and bring to the blockchain tech community.

What has been your experience developing on Tezos?

With Tezos, it’s really exciting as an engineer to be challenged to innovate and develop in a space that’s always evolving and growing. I have experience with smart contract development using Michelson, the native language for smart contracts.

I’ve also had the chance to implement Gravity’s own version of the Tezos DID Method and DID Manager, which are key components of our decentralized identity protocol on Tezos.

A DID Method is the mechanism by which a particular type of decentralized identifier (DID) and its associated DID document are created, resolved, updated and deactivated.

The Tezos DID Method specifies how Tezos can be used for DID creation and management, compatible with the issuance, storage, and verification of Verifiable Credentials. DID Managers are smart contracts on the Tezos blockchain that implement the Tezos DID method’s specific on-chain functionalities.

What tools do you like?

Personally, I like spoons. No, but really, I like Taquito. Each Tezos node exposes an http API so we can access them. Taquito wraps an http client in order to access the http API in a more convenient way.

What do you find most valuable about developing on Tezos compared to other blockchains?

I think the Tezos ecosystem’s focus on formal verification of smart contracts and on-chain governance is extremely important. And compared to Ethereum and Bitcoin, Tezos is cheaper, more efficient and better for the environment. Because Tezos is a liquid-proof of stake protocol, it also consumes less resources than the proof of work of other blockchains.

For me, elliptic curves are something that you don’t typically see as a developer. As someone with a math background, I see the importance of having a strong cryptographic mechanism, which Tezos offers. Because the language is extremely cryptic, it also allows developers to have greater control over what we’re developing.

What Tezos projects are you most excited about?

Everything is interesting, but I really like TZIP-16! It’s powerful, and you can have what we call “views functions” attribute getters and meta-data. It’s not only the smart contract, you also have this upper layer that allows you to have off-chain data.

It was great when I worked to integrate Gravity with the TZIP-16 standard. With this TZIP-16 implementation, now we can provide off-chain metadata during the resolution of DID Documents from DIDs.

What do you hope to see from the Tezos ecosystem in the future?

If something like OpenTimestamps appears on Tezos, it would be really exciting!

What’s on the horizon for Gravity?

Most people know about Gravity’s work with organisations like the UNDP Turkey, the Kenya Red Cross and the DIGID Project consortium of NGOs to leverage decentralized identity for improved humanitarian action (check out the latest case studies on our Medium blog to learn more).

As we continue to deepen our work in the humanitarian space, Gravity is also focusing on building out our supply chain finance (SCF) use case. In fact, we just released a new video to share how our digital ID solutions for supply chain financing work.

The idea is that our SCF solution builds trust among financial service providers, merchants and suppliers to unlock greater financing opportunities for all stakeholders.

Our tech team is really excited to be developing this solution, which uses decentralized ID and blockchain technology to enable small business merchants to create trusted financial identities using digital ID wallets that can give them access to affordable working capital and help them grow their businesses.

As an engineer, it’s awesome to keep building technology that can be leveraged for different real-world use cases and have such a big impact on people’s everyday lives!

To learn more about Gravity, follow us today!

Gravity is an ID2020-certified digital ID solution that empowers individuals, international organisations, and governments to create trusted decentralized identities that are private, portable, and persistent.

Our vision is to build human-centered digital ID solutions for easy, transparent, and secure data sharing for all people, anywhere in the world. For a more in-depth overview of Gravity’s work, check out our article here.

Website: www.gravity.earth

Twitter: @gravityID_earth

LinkedIn: https://www.linkedin.com/company/gravity-earth/

Medium: https://medium.com/gravity-earth

Telegram: @GravityID_earth

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