Welcome back to Day 2 of my blockchain series—this is where we run our first decentralized application on a private local devnet. The app we’re building throughout the series is a Rock Paper Scissors game where two players (Alice and Bob) can wager on the outcome without a third party in the middle. And yeah, you might be thinking, “Isn’t a third party what makes it fair?” But that’s the point: the third party can be unfair too, so why trust them when they don’t add real value and you don’t have to. In this video I scaffold the Reach backend in an index.rsh file by exporting a main Reach app and defining two participants: Alice and Bob. I also set up the frontend in JavaScript (index.mjs): I load the Reach standard library, create test accounts with a starting balance (using parseCurrency and newTestAccount), deploy the contract from Alice’s account, and connect Bob by attaching using the contract info. Along the way we hit real engineer stuff—like a tiny syntax bug (comma vs semicolon), setting the REACH_CONNECTOR_MODE for Algorand devnet via reach configure, and swapping deprecated deploy/attach calls for the newer contract API. By the end, the app doesn’t “do” much yet, but the full pipeline is running—and that’s the foundation we’ll build Rock Paper Scissors logic on next.