Solana Sets October 21 Launch for Alpenglow, Targeting 150ms Transaction Finality

In Brief: Solana will switch on its Alpenglow upgrade on October 21, 2026, with transaction finality expected to land at roughly 150 milliseconds. The migration retires the TowerBFT consensus mechanism and brings in new protocols for voting and for broadcasting blocks. Developers won't see major changes, while validators will need updated clients and will have to adapt to new voting processes. Alp