This week, we hardened the defenses of the Phase 0 fork choice rule. Much of our time is spent analyzing eth2 to ensure that the system can remain stable even under adverse conditions (e.g. a large attacker, a major network outage or partition, etc). With any large engineering project, the aim is to find as many potential issues and harden against these scenarios prior to release. This is why we’ve engaged with many external teams and researchers to perform audits, economic analysis, and formal verification of eth2, but at the same time as we move toward release, we must remain vigilant and flexible to respond to unforseen attacks in production (e.g. the Shanghai DoS attacks of 2016).