Omar U. Espejel
Building developer ecosystems and tools at the intersection of Crypto (L2 Scaling, ZK-Proofs) and AI (Transformers, Open Source). Focused on scaling complex systems through code, education, and community.
Last updated: March 31, 2025
Currently Senior Developer Advocate Engineer at the Starknet Foundation, driving adoption of Starknet L2 scaling. Concurrently, serving as After-Hours Lead Open-Source Builder of Restake Watch, an independent public goods monitor for the restaking ecosystem, supported by ~$75k USD in grants from the Ethereum Foundation and Obol Collective. Previously scaled developer onboarding for Cairo/Starknet at Starkware and developed core educational materials for AI models at 🤗 Hugging Face, including authoring 4 top-rated (5-star avg. across 325+ opinions) AI courses on Platzi, LATAM's largest online tech education platform. Presented ZK/L2 concepts at premier events like ETHCC, Devcon, and ETHPrague. Host of Hacia Afuera, the most listened-to Spanish tech podcast.
Previous Roles
- Developer Advocate Engineer at Starkware: Scaled Cairo/Starknet adoption by initiating and leading the Starknet Book (800+ GitHub stars, primary resource for 1000s devs), delivering technical workshops globally (Devcon, ETH Latam, etc.), and building foundational developer documentation.
- Machine Learning Engineer / Developer Advocate at Hugging Face 🤗: Simplified AI model adoption via core educational materials (courses, blog posts), including official Hugging Face content and highly-rated courses on Platzi (see below). Key contributions: embeddings guide, fastai integration.
Key Projects & Contributions (Starkware & Starknet Foundation)
- Starknet Book Lead: Initiated, led development, and maintained the primary educational resource (book.starknet.io) for the Starknet ecosystem, achieving 800+ GitHub stars.
- Starknet SF Hacker House 2023 Lead: Organized and led the largest hacker house in the Ethereum L2 ecosystem at the time.
- Cairo 1 Documentation: Authored significant portions of the foundational documentation, enabling early developer adoption.
- Starknet Provisions Program Contributor: Contributed to the Starknet token distribution program.
- Developer Mentorship & Grants Program Lead: Established and managed a program supporting developers and teams building on Starknet.
- Developer Ecosystem Analytics: Developed Python tool analyzing on-chain/GitHub data to track developer growth and activity, informing DevRel strategy.
- Starknet Basecamp Support: Delivered technical curriculum and support for Basecamp educational cohorts learning Cairo/Starknet.
- Global Workshop Delivery: Presented technical workshops on Starknet/Cairo at premier Ethereum events (Devcon, Devconnect, ETHCC) and regional hubs (ETH Latam, ETH Rio, ETH Argentina, ETH São Paulo, ETH Warsaw, ETHPrague).
- Community Building: Established and grew moderated Telegram developer communities (Spanish, Portuguese, NA).
Personal Projects
- Lead Open-Source Builder - Restake Watch: Independent public goods watchdog monitoring risks for the Ethereum restaking ecosystem. Secured ~$75k USD in grant funding from the Ethereum Foundation and Obol Collective to support its monitoring and analysis mission.
- Founder - Gradiente: Startup applying AI for legislative/regulatory intelligence extraction.
- Host - Hacia Afuera: The most listened-to Spanish-language technology and science podcast featuring leading experts in AI, Crypto, and Science.
Recorded Courses & Presentations
Podcast Guest Appearances
Publications & Writing
