Predictfully — on-chain prediction market

Context

Predictfully is an on-chain prediction market on Avalanche: binary and multi-outcome markets, live odds, quests and a leaderboard. The hard product constraint was onboarding — the audience includes people who have never held a wallet, so the crypto plumbing had to disappear behind a normal web experience.

What I did

• I led the frontend, a Feature-Sliced React SPA with lazy-loaded routes, a role-guarded admin section and an internal UI kit, set up so a growing team could add features without colliding. The part that mattered most was the wallet and auth layer, built on wagmi and viem with Reown AppKit and smart accounts by default: someone signs up with an email or a social login, with no seed phrase and no extension, and a full Sign-In-with-Ethereum handshake drops them into an ordinary authenticated session.
• Money movement runs on a split model. Custody actions — deposits, withdrawals, token approvals — are signed on-chain, and I unified the native and ERC-20 paths into one transaction lifecycle so the UI treats them the same, while the trades themselves are quoted and settled through the backend to stay fast. The buy and sell panel understands both shares and tokens, odds charts update live, market data refreshes in the background so prices move without a reload, and quests and a leaderboard turn a one-off bet into something people come back to.
• For releases I wrote a Playwright suite typed straight off the OpenAPI schema, so regressions get caught before they ship, and the whole thing deploys through Docker and GitOps across every environment without anyone doing it by hand.

Outcome

The market runs in production with fully automated deploys, and email-first smart accounts turned wallet setup from the main drop-off point into a sign-up form. The split between on-chain custody and backend trading kept the money verifiable on-chain while trading stayed as fast as any web2 exchange.