The Espresso Foundation's first global hackathon, Build & Brew, is launching on March 10, 2025. We’re excited to invite developers worldwide to compete for a $100,000 prize pool by deploying rollups integrated with the Espresso Network and building applications that leverage Espresso confirmations to create seamless cross-chain experiences.

Whether you’re new to development or a seasoned veteran, there’s something for everyone—and everyone who successfully completes the Caffeinate & Code core challenge is guaranteed a portion of the prize pool. Register here today!

Ethereum's fragmentation poses a critical challenge: how can L2s trust information from each other quickly and securely?

Espresso confirmations solve this by providing BFT consensus-backed transaction finality within seconds rather than the 12+ minutes (or days) required when L2s communicate via the L1. This enables near-instant cross-chain interactions with minimal trust assumptions, regardless of stack or VM.

This hackathon is your opportunity to build the connective tissue of Ethereum's future—where assets, data, and interactions flow freely between chains without sacrificing security or sovereignty.

The Espresso Build & Brew Hackathon features two main tracks, each designed to accelerate different aspects of the Espresso ecosystem with a combined prize pool of $100,000.

Track 1: Caffeinate & Code

• Core Challenge: Deploy functional rollups integrated with Decaf, Espresso’s testnet

• Mainnet Bonus

• Build Something Real

Track 2: Cracking Composability

• Best Composable Apps

• Open Intents Applications

This track rewards developers who deploy live, functional rollups using Arbitrum’s Nitro stack (i.e., Orbit chains) that are integrated with Espresso.

Every successful deployment on Decaf, Espresso’s long-running testnet, will receive a guaranteed share of the prize pool, making this a unique opportunity for teams exploring development of new chains.

Core Challenge ($30K shared) - Deploy a fully functional Orbit chain and integrate it with Decaf, Espresso’s long-running testnet, and Arbitrum Sepolia. All successful deployments will receive a share of this prize pool.

Whether you're building a specialized chain for a specific vertical or experimenting with a novel rollup design, all qualifying deployments earn rewards. Please check the submission guidelines to ensure your rollup meets the requirements and is eligible to receive a prize. Each developer/team can submit up to two rollups for this track.

Mainnet Bonus ($10K shared) - Take your rollup to the next level by deploying on Espresso Mainnet and Arbitrum One. Teams who successfully launch on mainnet will divide this additional prize pool, showcasing their L2 to real users and applications.

Build Something Real ($10K for top 5) - Beyond just deployment, we're rewarding the best implementations that have functional testnet deployments and a compelling pitch. Projects will be judged on innovation, technical implementation, and potential impact.

This competitive track rewards the most innovative cross-chain apps and experiences that leverage Espresso confirmations. To get your creative juices flowing, we’ve compiled some ideas of potential apps, protocols, and features that could be built by leveraging Espresso confirmations.

Best Composable Apps ($35K) - Develop applications that read from HotShot on an Arbitrum-Decaf rollup, demonstrating real cross-chain functionality. Prizes will be awarded to the most innovative and well-executed projects, with a focus on user experience and technical implementation. See the submission guidelines for the judging criteria.

Open Intents Applications ($15K) - Build projects that integrate the Open Intents Framework with Espresso confirmations in an Arbitrum-Decaf rollup. We're looking for applications that showcase how intent-based architectures can leverage fast confirmations to deliver superior cross-chain experiences.

The Espresso Foundation is excited to have the support of Espresso Systems, an early and core contributor to Espresso Network, in making this hackathon happen.

• Espresso Integration Overview - Start here for a high-level understanding of how Espresso confirmations work and integration options

• Chain Deployment Guide - Step-by-step instructions for deploying an Espresso-integrated Arbitrum Orbit chain

• Cross-Chain Development Guide - A guide covering the fundamentals of building applications that leverage Espresso confirmations. Coming soon!

• API Reference - Explore Espresso's APIs for developers

• Discord Community - Join the #build-and-brew channel in Discord for real-time support, connect with other participants, and post technical questions for the Espresso Systems team and community. First verify your build registration in the channel #builder-verification to open up the other hackathon channels.

• Office Hours - Espresso Systems will host weekly office hours on Fridays to give participating developers opportunities to tap Espresso Systems engineers for personalized support.

The future of Ethereum isn't a single chain—it's thousands of specialized chains working together. Join us in building the connective tissue that will unite Ethereum's ecosystem.

Learn more and register now to participate in Espresso's first global hackathon.

• Register: Join the hackathon at DoraHacks

• Prepare: Dive deep into the developer documentation to understand Espresso confirmations and integration options

• Connect: Join Discord for support and to find team members

Submit: Final submissions are due March 31, 2025