---
# System prepended metadata

title: Dev Update Week 1 (Robert Zajac)

---

# Dev Update Week 1 (Robert Zajac)

This is the week 1 update for *robzajac* in EPF Cohort Three.

My goal this week was to explore potential project ideas and narrow down a focus as well as next steps for the upcoming weeks.

## Update

### *Project goals*

I'm interested in working at the consensus layer and contributing to Ethereum decentralization & scaling. Based on some [proposed projects](https://github.com/eth-protocol-fellows/cohort-three/blob/master/projects/project-ideas.md) and my own research, I decided to investigate light client development for the CL.

### *Current state of light clients*
- Specs
    - Sync protocol (libp2p) https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md
    - Beacon APIs https://github.com/ethereum/beacon-APIs/pull/247
    - Portal network https://github.com/ethereum/portal-network-specs/tree/master/beacon-chain
- Implementations
    - Lodestar is go-to for client-server (LES) based light client https://github.com/ChainSafe/lodestar/tree/unstable/packages/light-client
    - Portal network clients, e.g. https://github.com/ethereumjs/ultralight

Additionally, there are several light client-based projects in progress from community members:
- A light client-based RPC proxy (e.g. for use in browser wallets) https://github.com/lightclients/kevlar
- Some work done in a past EPF cohort https://github.com/eth-protocol-fellows/cohort-one/blob/master/notes/Light-Clients-R%26D.md
- MVP of a Python light client communicating with Lodestar https://github.com/EchoAlice/python-light-client/tree/light-client
- Among likely others

### *Project Direction*
I'm interested in implementing light client endpoints for a production CL client. I may start in `teku` based on past language experience. I'm also interested in continuing to learn about the CL specs and more about Portal network implementation efforts.

Next steps:
- Deep dive light client sync protocols and APIs
- Meet potential mentors for consensus layer and client teams
- Identify a CL client in which to focus implementation

### *Additional readings*
- Light Ethereum Subprotocol (LES) networking https://github.com/ethereum/devp2p/blob/master/caps/les.md
- Notes from *ralexstokes* on requirements for a beacon chain light client https://notes.ethereum.org/@ralexstokes/S1RSe1JlF
- [Light clients after the merge](https://www.youtube.com/watch?app=desktop&v=ZHNrAXf3RDE) from Devcon
- Notes on why client diversity in the CL https://mirror.xyz/jmcook.eth/S7ONEka_0RgtKTZ3-dakPmAHQNPvuj15nh0YGKPFriA
- Consensus layer book from Ben Edginton https://eth2book.info/altair/