In a frenzy leading up to Ethereum’s much-anticipated merge, the network’s developers have deployed test after test to ensure that everything goes smoothly when the second-largest cryptocurrency by market capitalization switches to proof of stake next week.

Ethereum last test before the merge was a total success
Ethereum today completed what its developers describe as the “absolute final dress rehearsal” for the historic and massive upgrade, which is expected to occur between September 13 and 15.
The 13th shadow fork of the Ethereum mainnet went live earlier today, apparently without incident. Shadow forks are focused trial runs of aspects of the merge that test for potential issues and simulate the act of switching the Ethereum mainnet’s underlying mechanism from the current PoW model to PoS, effectively ending mining on the network.

A number of Ethereum developers confirmed today’s successful deployment of the network’s final shadow fork. “There were no issues,” Ethereum core developer Marius Van Der Wijden said.
The Ethereum network experienced some hiccups last week during Bellatrix, a critical pre-merge upgrade, when its “missed block rate” increased by 1,700%.
The missed-block-rate metric tracks how frequently the Ethereum network fails to validate a block of transactions. Normally, about 0.5% of blocks experience this problem; however, in the hours following the Bellatrix upgrade, that figure increased to 9%.
The snag was attributed by Ethereum’s developers to a lack of preparedness on the part of a number of node operators who had yet to update their clients to the proper merge-ready software. Node operators are the individuals and organizations responsible for maintaining the Ethereum network’s backend infrastructure.
25.2% of Ethereum’s nodes had yet to upgrade their software at the time of the Bellatrix upgrade.
According to Ethernodes, that figure has since dropped to 15.4%.
The team behind The Merge wants it to be “basically perfect”
According to Terence Tsao, an ETH core developer, today’s shadow fork tested this missed block rate issue and found it to be “basically perfect.”
For the last few months, the network’s developers have been running dress rehearsals of the merge almost weekly, attempting to game out any scenarios that could potentially derail or delay its execution. There is virtually no room for error with tens of billions of dollars in digital assets, apps, and decentralized finance instruments built on the Ethereum network.
Ethereum’s developers have consistently expressed confidence that the merger will go exactly as planned. Nonetheless, the test runs have continued, possibly for the sake of providing developers with some peace of mind.
“At this point, it’s just sanity checking,” Van Der Wijden explained.