Google’s Gemini 3.5 Pro slips months behind schedule
TL;DR:
- Gemini 3.5 Pro, promised for June at Google I/O, is months behind schedule as the company works to improve its capabilities, particularly coding, Bloomberg reports.
- A late-June refresh of the model’s training data fell short of expectations, according to ten current and former employees; Alphabet shares slipped nearly 3% on the report.
- The delay lands in a bruising fortnight for frontier releases shaped by US national-security intervention as much as by engineering.
Google’s most powerful flagship AI model is running months late. Sundar Pichai told the I/O developer conference in May that Gemini 3.5 Pro would arrive in June; instead, Bloomberg reports the company is still working to lift its capabilities — coding above all — after an update to the model’s training data produced disappointing results.
The account, drawn from ten current and former employees, describes engineers, researchers and managers worried as OpenAI and Anthropic ship models that outperform Gemini. Google’s response was measured: a spokesperson said the company is testing 3.5 Pro, an upgraded Flash model and others with partners, is “productively engaged” with the US government, and continues shipping quickly at customer-friendly prices.
The competitive context is unforgiving. OpenAI launched GPT-5.6, its most advanced model, last week — itself delayed by US government requests for early access over national-security concerns. Anthropic’s Fable 5 and Mythos 5 were disabled entirely for a fortnight under a June export-control order before safeguards satisfied Washington. Frontier release schedules increasingly answer to two masters: engineering readiness and government clearance.
A reality check with market weight
The delay fed a broader repositioning around AI expectations — the same day, investors were rotating away from chip stocks on slowing capex forecasts. It also sits oddly alongside Google’s own product confidence: the company chose this week to rebrand NotebookLM as Gemini Notebook, stretching the Gemini name across more surfaces even as its next flagship engine slips.
For UK businesses buying on roadmaps, the lesson is familiar: model release dates from every frontier lab, not just Google, are best treated as intentions rather than commitments.
Looking forward
Google says testing continues with partners, and a delayed-but-strong 3.5 Pro would quickly rewrite this story. But with Chinese open-weight models closing the gap at speed, the cost of months lost at the frontier is rising for everyone.