Carlo Esposito and Thragg
CastleDAO – for two weeks Superteam Ireland ran a developer residency at Slane Castle – here is one of the voices from Demo Day (read here for more)
Carlo Esposito is a solo founder who has been building software since he was nine years old. He started his first company at 19 and has worked primarily in native mobile development, using Kotlin for Android and Swift for Apple, as well as backend infrastructure and large-scale systems handling billions of requests each month.
Esposito discovered Web3 through Monero and was drawn to its emphasis on financial privacy. He began working with Solana around five months before the CastleDAO residency. He travelled to Slane to meet other builders, learn more about the ecosystem and become part of its community. Following the experience, he joined Superteam Ireland.
Tell us about the project you pitched at Slane. What is the idea, what problem are you trying to solve, and who is it for?
The project is called Thragg, a development environment for building Solana applications directly on a Seeker phone.
The idea grew out of another project I am building called Spettro, an open-source coding agent. The entire stack is open source and designed around privacy. We do not store or monetise users’ data.
Before Thragg, building on Solana generally required a laptop or desktop environment. Thragg explores the idea that developers should be able to create Solana applications directly from a phone, particularly on the Seeker.
The problem is mobility and accessibility. You might not always have your laptop with you, or you might be somewhere where using a full computer is impractical. In some parts of the world, a laptop is too expensive or impractical to own, while a phone is much more accessible. Thragg is aimed primarily at Solana developers, including people who are only beginning to explore development on the network.
I did not arrive at Slane planning to build Thragg. I had created a mobile app for myself as a development tool. Jonas from the Solana Foundation saw it on my phone and asked who had built it. When I told him I had, he asked whether it could run on a Seeker.
That made me think that, instead of simply adapting the existing app, I could build an environment designed specifically for developing Solana applications on the phone. Jonas lent me his Seeker so I could experiment, and Alejandro from Superteam Ireland later gave me a Seeker of my own to continue developing. That gave me the hardware I needed to turn the idea into a product.
What did you actually build during the two weeks? Did you start from scratch at Slane, build on something you were already working on, or complete a project already underway?
The project effectively started at Slane. I had an existing mobile development tool, but Thragg itself did not exist as a finished product. During the two weeks, I turned the initial idea into a working minimum viable product and then into something I could release publicly.
One of the biggest technical achievements was optimising the development process around Rust. I have primarily worked with languages such as Go and C++, so getting deeply into Rust was a valuable challenge. Solana development relies heavily on Rust, and I was able to optimise compilation on the phone to the point where some builds could be faster than completing the same work on a laptop.
I worked independently, but the people around me were extremely important. Jonas gave me the first Seeker I used to test the concept, Alejandro gave me a Seeker to continue developing on, and people including Serhiy provided valuable feedback on the user interface.
By the end of the two weeks, something that had not existed when I arrived had become a functioning product capable of building and deploying applications to the Solana blockchain directly from a phone.
Where is the project now? What worked, what changed during the two weeks, and what still needs to be built?
There is now a working product and the core functionality is essentially complete. Solana builders are testing it on their own Seekers and using it to build applications. My first tester was Jonas from the Solana Foundation, and I am now expanding the group of builders involved.
The biggest changes during the two weeks were technical. I learned a great deal about the Solana ecosystem, its libraries and how people are building on the chain. I also learned about optimising development workflows specifically for mobile hardware.
There is still work to do around optimisation and iteration. I want to add more capabilities and make the experience increasingly useful for developers, but the core product is working.
What is your longer-term vision for the project? If everything goes according to plan, what could it become over the next year or two?
I see Thragg as a possible foundation for a new generation of mobile-first Solana development. In the short term, I want Seeker users to be able to develop and deploy meaningful Solana applications directly from their phones. Over the next couple of years, I would like Thragg to become part of the infrastructure enabling many more applications to be created directly from mobile devices.
The most important part of the vision is not the software itself. Thragg is fully open source and free because I believe in free as freedom, rather than simply free as in price.
Success would mean seeing developers build on top of Thragg, contribute to it and help maintain it. Ultimately, I want to create a community of builders willing to develop and maintain strong open-source software together.
What did you think of the Slane experience itself? What was the best part of spending two weeks building alongside the other founders?
Slane Castle was an incredible environment for building. I particularly appreciated the green space around us. When you spend a long time coding and begin to feel burned out, being able to walk outside, get some fresh air, run or simply look at something other than a screen makes a huge difference. You return with a much clearer mind.
The other builders were probably the most valuable part of the experience. I learned about new technologies, libraries and approaches to building products, and received a great deal of feedback on the user experience.
As a developer, it is easy to optimise for other developers and forget how the experience feels to a normal user. The feedback pushed me to think much more seriously about the interface and the overall product experience. Many of the suggestions I received directly influenced what Thragg became.
What was the funniest, strangest or most unexpected moment at Slane?
Probably the most ridiculous part was the amount of time I spent awake. Because Jonas had lent me his phone, I was determined to get the first version working. At one point, I spent around 72 hours without sleeping while working in the kitchen at Rock Farm near the castle. By about 6 or 6.30am, coffee had stopped being enough, so I went outside and began using the wooden benches and tables for exercise to wake myself up.
There was also the cultural experience of being an Italian in Ireland. I do not think a day passed without someone offering me whiskey or beer. Everyone was incredibly friendly, which genuinely surprised me, and the sense of community was one of the things I enjoyed most.
Naturally, I had to cook proper Italian food before leaving. On the final day, I made carbonara for everyone. Finding all the ingredients in a small Irish village was slightly more difficult than expected, but everyone seemed to enjoy it, so I consider the mission successful.
There were plenty of cultural debates too. At one point, the Europeans ended up discussing whether Ireland and the UK drive on the wrong side of the road. As an Italian, I argued that if you drive on the right, you are right. There was also one person who apparently lost his shoes and walked around barefoot so often that everyone began calling him Frodo.
Finally, what happens next? What are you looking for now?
I am mainly looking for people who want to build on Solana and help develop Thragg further. The project is open source and free, and I want it to remain that way. It is primarily supported through donations, so people can contribute financially if they believe in what I am building. They can also contribute code, test it on their Seeker, report issues, give feedback, star the project or share it with other developers.
At this stage, I am particularly interested in finding more Solana builders who want to test Thragg and help shape what it becomes. The biggest need is people: developers, contributors, testers and anyone who believes that building software directly from a mobile device can open new possibilities for Solana development.
Project link: https://github.com/cesp99/thragg
