Now that the dust has settled, I want to take a moment to reflect on last week's Heimdall v2 migration. Validators were required to import the entire history of Heimdall v1 into an entirely new chain. The previous history had persisted since Polygon’s genesis, and all this had to happen while the chain continued to produce blocks! Its been said already but this really was the equivalent of open heart surgery. Heimdal v2 completely revamps the chains consensus engine, updating it from Tendermint to Comet BFT. It also integrates the ABCI v2.0 (a.k.a. ABCI++) module and now allows features such as pre-block validation and vote extensions. Aside from removing a ton of tech debt, the migration improves state sync between Polygon and Ethereum and reduces finality time to 🚨~5s 🚨. This monumental effort has taken months of meticulous planning and coordination, not to mention many hours of sacrificed sleep. Let's all take a moment to congratulate the stellar team and ecosystem of node operators that made this possible. 👏 One of the most sensitive operations during the migration was importing the genesis from Heimdall v1. With an incorrect history, Heimdal v2 nodes could have been corrupted, and the chain may not have been able to progress past the previous halt height. For this reason, a checksum of the existing Heimdall v1 state was generated, enabling operators to know that their import was correct. Here is a clip of this checksum being generated LIVE for the first time by Polygon core devs right before the migration process started. Enjoy!