2022 is the year Ethereum is set to complete its largest protocol change in history. Proof of Work (PoW), the environmentally unfriendly consensus mechanism Ethereum uses today (also known as mining) will be replaced by the much more eco-friendly, Proof of Stake (PoS) consensus mechanism. Consensys recently hosted a brown bag information session with three team members working closely on the Merge. Watch the session below as they break down the work their progress in 2021 and some 2022 goals. Following the video, you'll find takeaways.


  • Ben Edgington is a Product Manager for the consensus client Teku, also known as @benjaminion_xyz on Twitter. He posts regular updates on the future of Ethereum here: eth2.news

  • Mikhail Kalinin is a Researcher at Consensys R&D and has been at the forefront of developing the Merge specifications. He can be found on Twitter at @mkalinin2

  • Sajida Zouarhi is a Product manager for Hyperledger Besu and can be found on Twitter at @sajidazouarhi


Why Merge? Why Now? 

The reason the change from PoW to PoS is called “the Merge” is because the already running beacon chain will merge with the existing Ethereum mainnet chain. This preserves the history of the network, its functionality, but crucially changes the consensus mechanism. The beacon chain will coordinate data and the production of new blocks via network validators, which will use economic incentives to secure the blockchain (more info can be found here). At its core, the merge to PoS reduces network energy usage by at least 99.95%! Currently, the network has about the same carbon footprint as the entire nation of Finland and the ecosystem knows we need to do better. The Merge will also alleviate:

  • The Proof of Work consensus mechanism is not sustainable and not scalable long-term.

  • Proof of Stake makes participating in the network more attainable for many more users and not just large miners.

  • More equal distribution of network rewards to incentivize good behaviors and open up yield to many more users, despite a decreased issuance rate of ETH and smaller block rewards.

Pre-Merge versus Post-Merge Architecture 

Architecturally, the Merge is making use of the existing technology in Ethereum and supplementing it with what we need for the future. Current Ethereum clients, like Hyperledger Besu, will become known as “execution clients” and will handle state storage, block production, and smart contract interactions. “Consensus clients,” like Teku, will handle synchronizing state across the network and submitting transactions to the beacon chain. A new piece of technology called the “engine API” will allow these two clients to talk to each other extremely efficiently. All together, this new stack powers PoS with existing technologies and formats (like JSON RPC) and new ones such as REST APIs for the consensus clients. 

Though this may sound like a lot, there are only a few takeaways for node-runners and users: 

  • If you want to interact with mainnet post-Merge, you will need a combination of clients like Besu and Teku, i.e. Beku. Consensys develops both of these clients in house alongside open source communities and is testing this combo thoroughly for the Merge.

  • Existing dapps will still interact in nearly the same way and will require minimal updates.

  • The Merge will not solve scalability challenges right away, but is set to pave the way for sharding to improve data-availability and bandwidth. Users should look to rollups and L2s to scale immediately and lower gas fees.

  • Long-lived Merge test nets are coming! Sajida lays out the testing plan and how you can get involved here. An overall testing plan and how to get involved can be found here.

Help us Build the Future

Want to get involved or learn more? Join us on Discord at chat.consensys.net to give feedback, chat with us about the Ethereum clients Besu and Teku, and to get involved in the Merge community. Follow Ben’s eth2.news to get the latest updates on his newsletter. Reach out to us on Twitter at the handles above to start a conversation! BUIDLers, look here for new career opportunities at Consensys!