Arbitrum Ecosystem Fellowship - Final Report
Hi everyone,
This is the final report for the Arbitrum Ecosystem Fellowship, sponsored by Arbitrum DAO and powered by CoBuilders. It consolidates all five milestones in one place to close out the grant.
From May to September 2026, the program supported a cohort of 8 senior LATAM engineers with no prior blockchain experience as they shipped public infrastructure on Arbitrum Stylus. Along the way, we delivered two public open-source tools, a public interactive curriculum, a reproducible Stylus adoption report, and complete technical documentation. All five milestones are complete; links are below.
Executive summary
The Arbitrum Ecosystem Fellowship took a cohort of 8 senior LATAM engineers with no prior blockchain experience and helped them ship public infrastructure on Arbitrum Stylus. Across five milestones, the program ran a public selection, delivered a structured curriculum, supervised the build of two open-source tools, released them publicly, and closed with full documentation and a public ecosystem report.
The program shipped two public tools, the Stylus Ecosystem Dashboard (live) and the Stylus Compatibility Registry (published on crates.io), together with a public interactive curriculum, a reproducible Stylus adoption report, and complete technical documentation. Milestones 4 and 5 were submitted together as the final delivery.
Program at a glance
| Item | Result | |
|---|---|---|
| Cohort | 8 senior LATAM engineers (Cohort I), selected from 45 applications | |
| Curriculum | Public, 4 blocks / 18 modules: curriculum.cobuilders.xyz | |
| Tool 1 - Dashboard | Live analytics for Stylus adoption, with docs and an ecosystem report | |
| Tool 2 - Compatibility Registry | CLI + core library, published on crates.io (v0.1.0-beta.2) | |
| Documentation | Two docs sites (architecture, methodology, operations, reports, outcomes) | |
| Milestones | 5 of 5 completed | |
| Total funding unlocked | 18,000 USD |
Milestone 1 - Selection & Onboarding
Funding: 4,500 USD · Submitted: 18/06/2026 · Window: May 22 to Jun 18, 2026 · Status: 
Completed
A public call for senior LATAM applicants ran from 02/06 to 17/06/2026 across a landing page, X, LinkedIn, and LATAM developer communities on Telegram, drawing 9,606 combined impressions. Technical screening moved 45 applications through a uniform filter: 15 from LATAM, 12 eligible, 10 to technical interview, and 8 confirmed fellows who signed the program’s terms. We drafted the onboarding curriculum and built a qualitative cohort baseline through the selection conversations. The confirmed cohort is heterogeneous and complementary (backgrounds across JavaScript/TypeScript, Python, Go, and Java), all senior, all new to Arbitrum and Stylus.
Deliverables: confirmed and signed cohort, onboarding curriculum draft, and public-call materials. Landing page: fellowship.cobuilders.xyz.
Milestone 2 - Structured Educational Phase
Funding: 4,000 USD · Submitted: 27/07/2026 · Window: Jun 22 to Jul 26, 2026 · Status: Completed
A structured, part-time curriculum (about 9 hours per week) of four weekly blocks and 18 modules, Ethereum & the EVM, Arbitrum & the Nitro Stack, Stylus Fundamentals, and Advanced Stylus & Interop, published as a public interactive roadmap. Each block combined self-study, a supervised hands-on exercise (for example, Community Vault and Nitro Chain Monitor), and a live Q&A run in two mentor groups, all recorded. The two tooling tracks were defined and scoped in pairs, each with a public scope document, and the architecture was approved internally.
Deliverables: public curriculum (curriculum.cobuilders.xyz), scope documents for both tools, scaffold repositories, and Q&A recordings.
Milestone 3 - Supervised Development Phase
Funding: 4,000 USD · Submitted: 31/08/2026 · Window: Jul 27 to Aug 30, 2026 · Status: Completed
The cohort built the two tools in supervised teams. The Dashboard’s initial indexing logic tracks Stylus activity from the ArbWasm and ArbWasmCache precompiles (identifying Stylus contracts by their 0xEFF000 bytecode prefix) through an Envio HyperIndex indexer into PostgreSQL and a Hasura GraphQL API, and an early version of the Dashboard went live. The Compatibility Registry reached a working CLI prototype (Rust core and CLI, constraint checks, weakest-link scoring, curated TOML registry). We documented the data model and indexing logic. All fellows contributed, including original engineering: they investigated an indexer under-count bug, cross-checked on-chain counts against Dune, and proposed fixes through pull requests. Team-created issues were offered as labeled suggestions, not mandates.
Deliverables: two public repositories with working prototypes and architecture documentation. Live Dashboard: stylus-dashboard.up.railway.app.
Milestone 4 - Public Release Phase
Funding: 3,500 USD · Window: Aug 31 to Sep 13, 2026 · Status: Completed (submitted together with Milestone 5 as the final delivery)
The two tools were finalized and released publicly. The Stylus Ecosystem Dashboard was finalized and deployed to a public URL, indexing on-chain Stylus activity in real time. Both tooling projects were released as public open-source repositories, and the Stylus Compatibility Registry was published on crates.io as two crates, stylus-registry (CLI) and stylus-compat-core (core library), v0.1.0-beta.2, with usage documentation.
Deliverables: public dashboard deployment (stylus-dashboard.up.railway.app); public open-source release of both tooling projects (Dashboard, Compatibility Registry).
Milestone 5 - Documentation & Ecosystem Report
Funding: 2,000 USD · Window: Sep 14 to Sep 20, 2026 · Status: Completed (submitted together with Milestone 4 as the final delivery)
Comprehensive architectural documentation for both tools is published as two documentation sites (architecture, usage, methodology, deployment, and limitations). Fellowship outcomes and recommendations were published.
Deliverables: final documentation package (two docs sites) and public ecosystem report.
Milestone reports
Each milestone was reported and submitted individually. The full per-milestone reports:
| Report | Link |
|---|---|
| Milestone 1 - Selection & Onboarding | M1-Report |
| Milestone 2 - Structured Educational Phase | M2-Report |
| Milestone 3 - Supervised Development Phase | M3-Report |
| Milestones 4 & 5 - Public Release + Documentation & Ecosystem Report | M4-5-Report |
Deliverables index
| Item | Link | |
|---|---|---|
| Fellowship landing | https://fellowship.cobuilders.xyz/ | |
| Curriculum | https://curriculum.cobuilders.xyz/ | |
| Dashboard - repository | GitHub - CoBuilders-xyz/stylus-dashboard · GitHub | |
| Dashboard - live | https://stylus-dashboard.up.railway.app/ | |
| Dashboard - documentation | Stylus Dashboard · Documentation | |
| Dashboard - scope document | Notion | |
| Compatibility Registry - repository | GitHub - CoBuilders-xyz/stylus-compatibility-registry · GitHub | |
| Compatibility Registry - documentation | Stylus Registry · Documentation | |
| Compatibility Registry - scope document | Notion | |
| Compatibility Registry - crates.io (CLI) | crates.io: Rust Package Registry | |
| Compatibility Registry - crates.io (core library) | crates.io: Rust Package Registry | |
| Fellowship outcomes | Stylus Dashboard · Documentation |
Funding summary
| Milestone | Deliverable | Amount | Status |
|---|---|---|---|
| M1 | Selection & Onboarding | 4,500 USD | Completed |
| M2 | Structured Educational Phase | 4,000 USD | Completed |
| M3 | Supervised Development Phase | 4,000 USD | Completed |
| M4 | Public Release Phase | 3,500 USD | Completed |
| M5 | Documentation & Ecosystem Report | 2,000 USD | Completed |
| Total | 18,000 USD |
Project timeline
| Milestone | Phase | Window | Status |
|---|---|---|---|
| M1 | Selection & Onboarding | May 22 to Jun 18, 2026 | Completed |
| M2 | Structured Educational Phase | Jun 22 to Jul 26, 2026 | Completed |
| M3 | Supervised Development Phase | Jul 27 to Aug 30, 2026 | Completed |
| M4 | Public Release Phase | Aug 31 to Sep 13, 2026 | Completed |
| M5 | Documentation & Ecosystem Report | Sep 14 to Sep 20, 2026 | Completed |
Thank you to the Arbitrum DAO and the Arbitrum Foundation for supporting this fellowship, and to the cohort for the work they shipped. The tools, curriculum and report are public and open-source, and we hope they are useful to the wider Stylus ecosystem.
CoBuilders Team