The Ethereum Glamsterdam upgrade is currently targeted for H1 2026, representing a major shift back to Layer 1 structural improvements. As of April 2026, development is moving through rigorous testing phases to ensure the structural changes to block production do not compromise network stability. The upgrade introduces Enshrined Proposer-Builder Separation (ePBS) and Block-Level Access Lists (BALs) to overhaul the network's core architecture. These critical improvements enable parallel execution, aiming to scale Layer 1 throughput toward 10,000 TPS while enhancing decentralization and MEV fairness. The upgrade is currently in developer network testing phases, with activation on major testnets like Holesky and Sepolia expected in the coming months.