I'm one of the people most directly responsible for this outage. I take Sui outages extremely personally and am incredibly disappointed that this happened. I'll echo what @EvanWeb3 said: Moving fast is no excuse for outages. This outage was caused primarily by an edge case in gas smashing introduced by address balances. However, we did not ship this feature carelessly. We spent over 6 months testing address balances and tried as hard as we could to exercise every edge case and combination of features we could think of. Unfortunately, we were bitten by an edge case that we did not discover during testing. Again, this is not an excuse - it shows that our testing strategy was inadequate, despite how much effort we put into it. We did not have a systematic way to enumerate or discover all possible edge cases. We will be re-examining our approach in light of this. But I do want to emphasize that we did not ship this feature carelessly or in a rush. We made mistakes, but we were absolutely not operating in "move fast and break things" mode. One more thing: Address Balances is by far the biggest change to Sui's execution model that we have shipped, and we don't have any plans to ship anything this large and disruptive again. It was a necessary change to make Sui into what it should be, but we don't seek out huge disruptive changes like this for the sake of it. Now that the feature is out we will be redoubling our efforts to make Sui the most reliable L1. We have a lot of work to do, I'm excited to start on it!