MariusVanDerWijden on Ethereum Merge Expedition

Insights shared by MariusVanDerWijden on Ethereum's Journey to The Merge Upgrade

MariusVanDerWijden on Ethereum Merge Expedition

Ethereum Merge Day 👉🐼👈, i.e., September 15, 6:42:42AM UTC, is the day that Ethereum users, developers, or researchers will never forget. It was the day when their six years of hard work finally paid off. Marius van der Wijden is one of the key developers who has played an important role in The Merge. Here is a quick Post of our short Q&A with Marius van der Wijden on Ethereum Merge Expedition.

Q: How did Ethereum developers reach Shadow forking? Any story you would like to share?

  • We've talked about trying to copy the state and replay transactions already during testing for the london hardfork, however changing the blocks would mean we had to re-seal them. This is pretty difficult under PoW but very easy under PoS. So The Merge gave us a great opportunity to test Shadow Forking and the switch to Proof of Stake made it way easier to implement it.

We have covered all insights & bugs in all 19 shadow forks (6 Goerli Testnet Shadow Forks & 13 Mainnet Shadow Forks) in this article: Ethereum Mainnet Shadow Forking: An Overview.

Q: Why do you think Goerli is the last testnet to be merged?

  • It's the most important one for users and we wanted it to act as a good dress rehearsal for the big day. The others are either not going to be supported after the merge or don't have a lot of transactions on them.

Fun Fact: Someone stole around 244,285 Goerli ETH from Marius van der Wijden. In addition to this hacker has also stolen 1,013,010 ETH on Ropsten, 38 ETH on Kovan and 2580 ETH on Rinkeby. If all of this ETH was real, then hacker would have made around 1791331704 USD. This hack was made possible because Marius published his private key on GitHub.

Ethereum blockchain has finally transitioned to Proof of Stake consensus with The Merge upgrade. It is anticipated that Ethereum devs will retain Sepolia, a PoW testnet, and Goerli, the current PoA/PoS test network. Here is a quick post on Ethereum Testnets after The Merge.

Q: How convenient was spinning up a new beacon chain for existing PoW testnets?

  • It was not too bad, the hardest things were deciding on who gets to run validators and timing the forks correctly.

If our readers want to know more regarding Ethereum testnets, then we will recommend them to read our extensive research report on the Evolution of the Ethereum testnets from genesis till the Merge upgrade. Sincere thanks to Tim Beiko, Péter Szilágyi, MariusVanDerWijden & Pooja Ranjan for reviewing and sharing details to be added to this report.

Q: Can you share some helpful tools used for testing the Merge testnet?

  • We set up blockexplorers and beaconchain explorers as well as launchpads and faucets so that home stakers could join the testing efforts. We also used transaction spammers like txfuzz to generate load on the networks.

Q: General experience of Merge testnets? Anything in specific that you would like to share with the community?

  • All things considered it went very smooth. In the beginning we had some issues with the spec, but that really solidified during amphora and the devnets. For the last ~6 months we only found issues with specific implementations or small oversights in the spec. I would like to thank the community members who participated in #TestingTheMerge and found countless little issues and helped us be very confident in our implementations.

Still having More doubts? Then, Readers can read Facts & Useful Resources for catching up with The Ethereum Merge. Here, we have answered all popular questions related to Ethereum Merge.

Related Videos


Disclaimer: The information contained on this web page is for education purposes only. Readers are suggested to conduct their own research, review, analyze and verify the content before relying on them.

To publish press releases, project updates and guest posts with us, please email at

Subscribe to EtherWorld YouTube channel for ELI5 content.

Support us at Gitcoin

You've something to share with the blockchain community, join us on Discord!

Follow us at Twitter, Facebook, LinkedIn, and Instagram.

Share Tweet Send
You've successfully subscribed to
Great! Next, complete checkout for full access to
Welcome back! You've successfully signed in
Success! Your account is fully activated, you now have access to all content.