Google’s Gemini 3.5 Pro Slips Further Behind Schedule After Reported Rebuild

(WS News) – Google is months behind schedule on releasing Gemini 3.5 Pro, its most advanced AI model, after reportedly scrapping an earlier version and rebuilding it from scratch to address weaknesses in coding performance, according to people familiar with the matter.

The model was expected to launch in June following its unveiling at Google’s developer conference in May, where CEO Sundar Pichai told a crowd of developers to “give us until next month to get it to you.” That deadline passed without an official release, and Google updated the model’s training data late last month in an attempt to improve coding performance, though the results reportedly disappointed internal teams. Alphabet shares fell as much as 3.2 percent following reports of the delay.

The company has said only that it is testing Gemini 3.5 Pro, an upgraded Flash model and other systems with partners, including discussions with the US government about the model’s capabilities and testing standards. Gemini 3.5 Pro remains in limited enterprise preview on Vertex AI, while its sibling model, Gemini 3.5 Flash, is already generally available and has drawn mixed reviews, with some users reporting it consumes tokens quickly during long tasks.

The delay has reportedly frustrated Google engineers and researchers concerned the company risks losing ground to competitors, and comes as rival labs have pushed out their own flagship releases in recent weeks. Google is also facing separate scrutiny over its expanding use of AI in search, with a recent report raising concerns about the risks AI-powered search features pose to children.