Arbitrum Day – Brazil Chapter
Final Report
Milestone 04 | Onsite Execution – Hackathon, Conference & Arbitrum Day + Milestone 05 | Post-Event Wrap Up
Executive Summary
Arbitrum Day - Brazil Chapter was held on November 9 as part of ETH Latam São Paulo 2025, a four-day program positioned strategically ahead of Devconnect Buenos Aires. ETH Latam gathered 1,800 participants from more than 27 countries, including developers, founders, researchers, institutions, VCs, companies, and students.
The Brazil Chapter was designed to offer Arbitrum a high-visibility and high-context presence in the largest and most influential crypto market in Latin America. Throughout the event, Arbitrum maintained strong positioning through technical programming, on-site activation, hackathon engagement, media visibility and direct interaction with the broader Ethereum community.
More than 200 participants attended Arbitrum Day sessions throughout the program, and the Arbitrum-branded presence was sustained throughout the entire ETH Latam week.
Arbitrum Presence at ETH Latam São Paulo 2025
Visibility and Branding
Arbitrum maintained continuous visibility across the venue through stage design, signage, printed materials and branded totebags distributed to all participants.
Venue production was executed by Acaso, a São Paulo–based agency responsible for stage construction, decoration, assembly and teardown.
Community Engagement
Across the day, more than 200 participants attended Arbitrum sessions, including developers, operators, founders, researchers, and institutional representatives. Arbitrum maintained a strong presence across all four days of ETH Latam through:
- branded materials
- participation in the main conference
- hackathon incentives
- technical workshops
- ambassador engagement
- continuous media and social visibility
We had the pleasure of welcoming Vitalik Buterin to the venue on the day of Arbitrum Day, his first visit to Brazil. His presence generated significant community interest throughout the venue and contributed to the day’s unique atmosphere.
Media Coverage and Social Amplification
Arbitrum benefited from extensive visibility across regional media outlets and social channels.
Social media coverage included:
- Community recaps
- Ambassador-led content
- Speaker publications
- Reels and videos from ecosystem partners
- PT and ES content promoting Arbitrum programming
Press coverage (coordinated with Sherlock Communications):
- BeInCrypto (BR and ES editions)
- LatamBlocks
- Yahoo Finance
- Additional Brazilian media outlets covering ETH Latam and Arbitrum’s role
Newsletters:
- Blockchain Rio (20,000+ subscribers)
- POK (distributed to 1,200 universities)
Streaming
A five-hour livestream of Arbitrum Day sessions expanded reach to international audiences:
https://x.com/i/broadcasts/1YqGolWZOOgJv?s=20
Arbitrum Day Schedule
Arbitrum Day included technical talks, panels, mentoring sessions and jury participation for hackathon submissions.
Programming covered infrastructure, scaling, privacy, real-world applications and Arbitrum’s growing role within the Latin American ecosystem.
You can check here the slides:
- Expanding Arbitrum in Brazil and LatAm, by João Kury (Arbitrum Foundation): https://drive.google.com/file/d/1gHhR1DKzIffoACvEMokToNHYi0IEmYIG/view?usp=drive_link
- Confidential Smart Contracts, by Alexandre Carvalheira (Fhenix): [PTBR] The role of encrypted computation in decentralized systems
- 2026 will change everything about payments, by Konrad Urban (Peanut): EthLatam 2025 Talk - Why 2026 will change everything about payments - Google Slides
- Why Institutions Are Choosing Arbitrum, by Ricardo Gordon (Arbitrum Foundation): v2_EthLatam <> ArbiDay presentation _ Ricardo Gordon.pptx - Google Slides
- Resolvendo Casos do Mundo Real na Arbitrum, by Jean Putzel (Kleros): Copy of eth latam 2025 Kleros Mundo Real - Google Slides
- The Future of InfoFi, by Mel (Frutero Club): https://www.canva.com/design/DAG4NSQLdww/_WZ4NIe3WRpEVuHsCOiqhg/edit
(We are waiting for two slides more)
Complementing the on-site activities, two pre-hackathon workshops were delivered:
- Introdução a Arbitrum:
- Desenvolvendo em Arbitrum
These workshops provided a structured technical foundation for developers building with Arbitrum during the hackathon.
On-Chain Activations Enabled During ETH Latam
ETH Latam São Paulo also facilitated a series of on-chain activations showcasing the practical use of Arbitrum-based tools in real environments.
Merchant Onboarding: Mahá Restaurant
In early October, El Dorado onboarded Mahá, a local restaurant next to the venue.
Mahá processed more than R$ 2,000 on-chain during ETH Latam, marking its first-ever use of crypto. A simple user interface and clear onboarding guide enabled seamless adoption.
El Dorado also onboarded new individual users, including Serafin, a non-crypto user who executed his first peer-to-peer USDT purchase on Arbitrum to redeem a Red Bull at ETH Latam.
Reference: https://x.com/eldoradoio/status/1990933658111520877?s=20
Peanut Wallet Activation
Peanut Wallet contributed to on-chain adoption by offering 20% off on any Pix payment made through its application during the event, encouraging experimentation with Arbitrum-enabled payment experiences.
These activations demonstrated tangible real-world impact and helped drive both merchant and user engagement with Arbitrum infrastructure.
Hackathon Participation and Bounty Awards
ETH Latam’s Real-World Ethereum Hackathon gathered 317 participants from 12 countries and produced 31 submissions. Arbitrum played a central role through mentoring, jury participation and a dedicated bounty track.
Bounty Distribution (Total: USD 5,000)
1st Place – FHEVesting (USD 2,000)
Confidential vesting with ZK proofs + FHE.
2nd Place – Onflow Chain (USD 1,500)
Transparency infrastructure for payment and supply-chain data.
3rd Place – DriveFi (USD 1,500)
Privacy-preserving telemetry and parametric insurance logic.
Trends Across Submissions
- Expansion of ZK and FHE experiments
- Payments and tokenization with real-world integrations
- AI-driven agents and autonomous workflows
- Identity and on-chain reputation models
Full documentation was submitted in the hackathon wrap-up file.
Quantitative Metrics
| Metric | Value |
|---|---|
| Total ETH Latam attendees | 1,800 |
| Hackathon participants | 317 |
| Hackathon submissions | 31 |
| Countries represented | 12 |
| Arbitrum Day attendance | 200+ |
| Livestream duration | 5 hours |
| Arbitrum bounty pool | USD 5,000 |
Key Learnings
Audience Flow and Unanticipated Variations
The presence of Vitalik Buterin — on his first visit to Brazil — generated unplanned shifts in audience flow, as participants moved across the venue to interact with him.
Cultural Differences in Attendance Patterns
Event scheduling preferences differ across regions. Weekend events perform strongly in Argentina, whereas weekday conferences attract higher attendance in Brazil. As the venue was pre-booked, Arbitrum Day occurred on a Sunday.
Parallel Programming and Fragmentation
The SheFi Summit ran concurrently at the venue, concentrating part of the audience in a separate track. Additionally, many attendees used the day for networking, contributing to audience fragmentation.
Coordination with Local Ambassadors
Coordination with the Arbitrum Brazil ambassador group was lower than expected due to reduced operational bandwidth on the ETH Latam / ETH Kipu side. The team acknowledges and appreciates the support of Netto and Modular Crypto, who played an essential role in facilitating execution and documentation.
Conclusion
Arbitrum Day Brazil Chapter successfully delivered a high-visibility activation for Arbitrum within ETH Latam São Paulo 2025. The initiative reached diverse stakeholders, like builders, companies, institutions, students and first-time users, while fostering real-world on-chain activity through partner activations.
The event strengthened Arbitrum’s positioning in Brazil, enabled high-quality technical education, generated strong community engagement and produced a significant amount of Portuguese-language content that can now be reused and disseminated across the region.
The grant objectives were fully achieved, and the execution contributed meaningfully to Arbitrum’s presence and narrative in Latin America.