Anatoly Yakovenko stood on stage at Consensus Miami 2026 and told a cheering crowd that Solana would soon upgrade to Alpenglow. A live testnet, launched within a week, was proof. He said the upgrade was basically due sometime this year, maybe next quarter. But behind the applause, things were different.
The Alpenglow upgrade is supposed to be the biggest consensus change in Solana’s history. It aims to replace proof-of-history, the mechanism that has ordered transactions since day one. Validators approved the change in September 2025 with 98% support. Anza, the development firm behind the rollout, marketed it as a 100x improvement, cutting finality from 12.8 seconds to around 150 milliseconds.
Testnet launched, then broke
Yakovenko spoke on May 5. Days later, the testnet went live on a cluster. It broke almost immediately. Anza spokesperson Max Resnick told Decrypt on May 11 that the launch was a really exciting milestone. He did not mention that the migration had failed and been restarted.
The real story came out on the Solana Foundation’s weekly validator call on May 14. Anza engineer Ashwin Sekar confessed that over 40 nodes joined the cluster running Alpenglow. Then the migration broke.
“As usual, the first try did not work,” Sekar said on the call. He described a bug in the most recent master commit of TowerBFT and proof-of-history. TowerBFT is Solana’s proof-of-history-compliant consensus algorithm. Anza pushed a hotfix and tried again. A second bug appeared, where a validator accidentally banned peer connections. Both were patched.
Bugs hidden from media
None of these errors made it into mainstream press cycles. Outlets like TheStreet, Decrypt, and CoinMarketCap reported the testnet launch as a clean success. Anza’s framing of a well-executed migration was not challenged. Coverage of the bugs remained mostly on YouTube, within a small audience who bothered to watch a recording of the validator meeting.
Yakovenko’s next-quarter claim, made in early May, suggests a mainnet activation by September 30, 2026. That timeline might be optimistic. Solana’s mainnet has halted multiple times in its six-year history, including four outages within a single 12-month period. The upgrade is important, but the road ahead looks bumpy.
