ETHWarsaw is supporting Arbitrum Open House London
Apply for the Open House Buildathon and compete for $115K in prizes
If you’re tired of just winning hackathons, and want to go from hackathon winner to start-up founder, this one’s for you.
We’re excited to share that ETHWarsaw is supporting Arbitrum Open House London, the next stop in Arbitrum’s 2026 global builder program.
Following the success of Open House New York which brought together 1,700+ builders, 177 project submissions, and awarded over $340K in prizes & grants, we’re raising the bar in London with $415K in total prizes and grants for ambitious teams building on Arbitrum.
The program is split into two independent tracks, and builders can apply for either one or both.
Phase 1: Online Global Buildathon (May 25 – June 14, 2026)
A global, open-to-all online buildathon designed for teams already building or ready to start building on Arbitrum. Selected teams will compete for $115K in prizes and grants across General and Agentic AI tracks, and alongside a dedicated Robinhood Chain track.
Only 6 days left to apply for the Buildathon.
Pro tip: If you are applying to both the Buildathon and Founder House, use your time in the Buildathon for early iteration and take your project to the next level at the Founder House.
Register for the Buildathon → https://arbitrum-london.hackquest.io/buildathons/Arbitrum-Open-House-London-Online-Buildathon?utm_source=partner-ethwarsaw&utm_medium=social&utm_campaign=oh-london-buildathon
Phase 2: In-person Founder House in London (July 10 – 12, 2026)
A curated in-person residency for high-conviction founders building within the Arbitrum ecosystem with access to direct technical and GTM feedback from Arbitrum Foundation, Offchain, and ecosystem partners
Selected teams will receive access to $300K in prizes and grants across General, Agentic AI, and Robinhood Chain tracks, alongside direct ecosystem support.
Apply for Founder House → https://luma.com/openhouse-london?utm_source=partner-ethwarsaw&utm_medium=social&utm_campaign=oh-london-founder-house
Never Stop Building