2026-11-04 –, Workshop 2
A few months ago, Ream was an Electra client that only ran on its own devnet. We'll tell the story of adding PeerDAS, getting it to talk to other clients in Kurtosis, and finally watching it follow Ethereum mainnet and run a validator on Hoodi.
Along the way, we'll share what Fusaka really asks of a consensus client, and the bugs we only found once real peers showed up.
Fusaka changed how every consensus client handles blob data, peers and the beacon state. We took Ream through it in five steps, some with two tracks in parallel:
- Closing the gap against the Fulu consensus-specs.
- Full-custody PeerDAS, where blocks wait for their data, alongside range sync.
- Kurtosis interop with other clients, alongside backfill sync.
- Custody mode: storing only the columns a node is responsible for.
- Following Ethereum mainnet, alongside running our own Hoodi validator.
We'll share what broke on the way: spec mismatches like the fork digest that only showed up next to other clients; sync that held up on a devnet but stalled on a live network; validator APIs that external validator clients couldn't use, so our validators missed votes; and state processing that took seconds per mainnet block until we reworked it.
If you build or maintain a consensus client, you'll leave with a practical picture of what it takes to make one work on post-Fusaka Ethereum.
Blockchain researcher and engineer focused on Ethereum protocol research, data availability, consensus, and cryptography. Ethereum Protocol Fellowship (EPF) participant and co-author of research on efficient Data Availability Sampling using coded distributed arrays. Interested in building secure and scalable decentralized systems.
A blockchain engineer from Vietnam, focused on Ethereum protocol research, data availability, consensus, and cryptography. I also co-authored a published paper on the network layer for data availability sampling.
I joined EPF cohort 7 to learn from the people who build the protocol, and I've always hoped that one day my work could make a real difference to blockchain technology.