# EPF6 Dev Updates – Week 4 This week I was able to complete some tasks from week 4 goals: - I dived through [Lodestar technical walkthrough](https://www.youtube.com/watch?v=wqQDomhpZeQ), a good insight into the Lodestar's codebase by Cayman from the Lodestar team itself. This helped me to get idea about the overall flow. I also further explored more networking, peering related parts of the codebase. - I explored peerDAS [EIP](https://eips.ethereum.org/EIPS/eip-7594) and [related spec changes](https://github.com/ethereum/consensus-specs/tree/9d377fd53d029536e57cfda1a4d2c700c59f86bf/specs/fulu/) in general to get an overall idea and specifically changes that will affect blob retention with the custody column groups. More specifically the [reqresp domain changes](https://github.com/ethereum/consensus-specs/blob/9d377fd53d029536e57cfda1a4d2c700c59f86bf/specs/fulu/p2p-interface.md#the-reqresp-domain) with `DataColumnSidecarsByRange v1` and `DataColumnSidecarsByRoot v1`. - I started writing basic backfill algo from scratch. Some more changes needed before I get feedback from my mentor. Then, I decided to run different EL + CL combinations and analyse backfill related metrics data with different inital states of db, so that I can get exact performace insights about the clients and then deep dive into the codebase of best performing clients. Did lot of experimentation around this but was unable to efficiently run node due to my university's firewall restrictions and ISP restrictions. Will try more workarounds the next week. Week 5 goals: --- - Analyse different EL+CL metrics related to backfill - Project proposal presentation for epf office hours - Draft project proposal - Dive into Lighthouse's backfill implementation