# EPF Dev Update #9 I noticed that my weekly updates were getting too short, so I decided to turn them into bi-weekly updates. This update contains my work done on weeks 9 and 10 of the EPF (2023-09-04 to 2023-09-24). **tl;dr:** - Presented my new project proposal. - Dived into the Engine API. - Published my Kademlia article on the portal network website. ## New project proposal presentation I presented my new project in week 9. You can see my [slides here](https://github.com/eth-protocol-fellows/cohort-four/blob/master/notes/danielrachi/slides.pdf) and the [recording here](https://drive.google.com/file/d/1It9kVsv19-BWtPYYzjY00jhOf2E42_vi/view) (I presented last, since it was my second time). ## Engine API dive After my research on [the Flashbots architecture](https://hackmd.io/@danielrachi/HJxXjUwC2), I realized that it doesn't make a lot of sense to continue on that road without having a better understanding of the Engine API. I started my dive on the specs. Specifically: - [Shanghai engine API spec](https://github.com/ethereum/execution-apis/blob/main/src/engine/shanghai.md). - [Shanghai execution spec](https://github.com/ethereum/execution-specs/tree/master/src/ethereum/shanghai). - [Capella consensus spec](https://eth2book.info/capella/annotated-spec/). I quickly realized that I wasn't going to get to the point where I wanted by reading the spec. So I started reading the Lighthouse codebase. To be more specific, I started reading what the procedure was to start a Beacon Node, focusing on how the execution engine was represented and how the interactions with it worked. (Similar to [Jimmy's article](https://hackmd.io/@jimmygchen/Sk9oPHO8s), but with a different focus.) Learning about the Engine API this way has been great. I feel like I have a much better understanding of how everything fits together. The downside is that this is taking me much longer than I expected, but I think this would be the case no matter what approach I take. I'm working on an article that goes deeply into the most important Engine API flows, including the beacon node startup process. This article will contain a series of sequence diagrams to help understand the flows better. I mention the diagrams because it's something that can be specially useful to some people, and there has been some discussion on them already: [1](https://discord.com/channels/890617081744220180/890617129425047583/1149426208174518433), [2](https://discord.com/channels/595666850260713488/843176491386667018/1151886816702631937), [3](https://discord.com/channels/595666850260713488/1152755207588020264). The article is not finished yet, but in the future you'll be able to find it [here](https://hackmd.io/@danielrachi/Bk6CELky6). ## Published author I opened a [pull request](https://github.com/ethereum/portal-website/pull/7) to the new portal network website that adds the article I wrote about Kademlia several weeks ago. It got accepted, and I just think it's cool that one of my writings was useful enough to be added to the main docs of a project :grin:. You can read it [here](https://www.ethportal.net/resources/protocols/kademlia).