Ethereum Protocol 101 by Mario Havel

​Course 2/7: Consensus & Execution: The Two Engines of Ethereum.

​Ethereum today runs on two tightly coupled systems:

• ​The Consensus Layer (CL) — responsible for fork choice, finality, and validator coordination

• ​The Execution Layer (EL) — responsible for transactions, the EVM, and state transitions

​In this session, we’ll unpack:

• ​How Proof-of-Stake consensus works

• ​What changed after The Merge

• ​How validators propose and attest to blocks

• ​How the Execution Layer processes transactions

• ​How the Engine API connects CL and EL

​Understanding this separation is essential if you want to:

• ​Read client code

• ​Follow All Core Devs calls

• ​Contribute to research

• ​Join client teams

​If you’ve heard terms like “Gasper,” “fork choice,” or “state transition function” and want them to actually make sense — join us.