The Arbitrum Foundation has opened applications for Open House Singapore, the Southeast Asian edition of its global founder program. The initiative combines a three-week online Buildathon with a subsequent in-person Founder House, giving developers and early-stage teams access to technical support, product feedback and commercial mentorship. Open House Singapore extends Arbitrum’s builder program into Southeast Asia after earlier editions in New York and London.
The online Buildathon will run from September 14 through October 4, with participants able to develop an existing project or start from scratch. Builders can use Solidity or Stylus, which supports Rust and other WebAssembly-compatible languages, and qualifying projects must deploy on an Arbitrum-based chain such as Arbitrum One, Arbitrum Sepolia or Robinhood Chain. The program is structured around producing working onchain applications rather than completing a purely educational course.
Buildathon Offers $115K Across Prizes and Grants
The Buildathon carries $70,000 USDC in its main category, divided between first, second and third place at $40,000, $20,000 and $10,000. Another $15,000 is reserved for a Promising Products track covering areas such as AI agents and new financial primitives, while up to $30,000 is available through milestone-based grants. The online phase therefore provides as much as $115,000 in direct prizes and development-linked funding.
Prize distribution also reflects Arbitrum’s expanding chain ecosystem. At least one of the top three main-category positions and one Promising Products award are reserved for projects building on Robinhood Chain. The top three overall Buildathon teams will additionally earn places at the three-day Founder House in Singapore. Winning teams receive a path from online development into direct, in-person product and founder support.
Participants will work with teams from the Arbitrum Foundation, Offchain Labs and ecosystem partners through feedback sessions and workshops spanning product development, user experience, go-to-market strategy, fundraising, agentic commerce and wallet infrastructure. The curriculum combines technical execution with the commercial work required to turn a prototype into a viable product.
Singapore Continues Arbitrum’s Global Founder Strategy
Open House Singapore has $415,000 earmarked across its Buildathon and Founder House programs, jointly supported by the Arbitrum Foundation and Robinhood Chain. The format follows Open House London, where Arbitrum reported 350 online builders, 278 submitted projects and 140 founders participating in the in-person phase. The Singapore edition builds on an existing accelerator format rather than introducing an entirely new ecosystem initiative.
The technical options available to teams are broader than the original description of an Orbit-and-Stylus track. Arbitrum’s documentation supports Solidity applications, Rust smart contracts through Stylus and dedicated Arbitrum chains with configurable execution, gas, governance and data-availability parameters. Builders can therefore choose between deploying an application on an existing Arbitrum network or developing around customized chain infrastructure.
For Arbitrum, the measurable outcome will come after the competition. Prize allocations and mentorship can accelerate development, but they do not demonstrate that resulting applications will attract users or sustainable funding. Open House Singapore’s longer-term value will depend on whether Buildathon projects continue operating after the program and convert technical prototypes into durable onchain businesses.