For our Designing Smart DeFi Savings virtual hackathon, developers spent three weeks competing to build the best consumer savings experience using the YO SDK. The goal was to create a product that makes onchain yield feel simple, trustworthy, and useful every day.

Products were judged on UX simplicity, creativity, growth potential, integration quality, and safety. While there were many great builds, only three can be winners. So, without further ado, the winners are:

🥇First Place - Yoyo

Yoyo is a mobile savings app that replaces the complexity of DeFi with a single AI chat interface. Tell Yoyo what you're saving for, and the AI will check rates, recommend the best vault, set a savings goal, and present a one-tap deposit confirmation. The AI chat is powered by DeepSeek Chat, with voice input via Groq Whisper. Yoyo uses YO to generate yield for your custom savings accounts.

Yoyo was chosen because of its user-centric design. By incorporating features like email sign-in and funding accounts with credit cards, Apple Pay, and Google Pay through Moonpay, Yoyo is exactly the kind of product that an everyday person would use to save. The inclusion of an AI chat gave Yoyo a creative edge, and the feature directly aligns with the rise of AI technology in today’s world.

The Yoyo builder won $1,500 USDC + 15,000 $YO.

Learn more: https://dorahacks.io/buidl/40831/

🥈 Second Place - YO Treasury

YO Treasury is an app that wraps all YO vaults into a single position and securely manages that position through an AI agent. Users deposit once (USDC), and an AI copilot handles the rest — allocating across YO vaults, swapping between assets, and rebalancing — all executed as atomic batch transactions with a single wallet signature. The user's dashboard always shows exactly where their funds are, how much yield they're earning, and the full state of their portfolio.

YO Treasury is geared more towards DeFi pros, but the app still simplifies yield optimization for these users. The design was architecturally ambitious, introducing PlasmaVaults, ERC-4626 vaults on Base that are configured with specialized action modules called fuses that connect to yoVaults. Despite implementing a complex concept, YO Treasury manages to keep the UX simple and easy to use. Adding an AI agent to assist with allocations was inventive and helped YO Treasury stand out from the rest.

The YO Treasury builder won $1,000 USDC + 10,000 $YO.

Learn more: https://dorahacks.io/buidl/40731

🥉 Third Place - Nestora

Nestora makes onchain savings simple and trustworthy, turning vault mechanics into clear, goal-based strategies anyone can use with confidence. Users create goal-based pockets, deposit any token, and earn yield automatically through YO. The goal-based savings accounts feature progress tracking and milestones.

Nestora’s concept of pockets, savings goals with targets and timelines, removes the complexity of DeFi, making it an ideal consumer-friendly product. Nestora features email, social, and Farcaster login via Privy, which removes one of the primary onboarding barriers users face with DeFi.

The Nestora builder won $500 USDC + 5,000 $YO.

Learn more: https://dorahacks.io/buidl/40119

Honorable Mentions

Choosing just three winners was a challenge, given the caliber of the builds we saw. Two projects, in particular, captured our attention for their unique approach to building with the YO SDK:

Shinjo: Shinjo is a savings app that turns saving into a game. Users deposit into YO-powered vaults that generate yield, and that yield funds a prize pool. Depositors are entered into random prize draws instead of earning small, steady interest.
YoCA: YoCA enables users to park their DCA (Dollar-Cost Averaging) funds in yield-bearing vaults, so their capital earns interest while waiting to be gradually deployed into target assets.

Conclusion

Congratulations again to all of our winners! If you’d like to see all the BUIDLs from Hack with YO, visit the BUIDLs tab of the hackathon page