FrontierThe story, in brief
Jev introduces a new shape of LLM - System One, aka Decision Models
Jev just introduced 'Decision Models'—a fundamentally new LLM architecture. Here's what changes.
The KeyNews take
Why it matters
A new model architecture category ('System One') claims to handle reasoning and decision-making differently than scaling transformer chains. If validated, this shapes how practitioners think about model selection and training for agentic workloads.
The key facts
5 to knowJev introduces 'Decision Models' (System One) as a new LLM shape
Architecture differs from traditional scaled-transformer approaches
Positioned for reasoning and decision-making tasks
Announcement via Simon Willison's coverage (Sep 21, 2026)
No benchmark data or comparative performance metrics provided in headline
Go to the source
Simon Willisonsimonwillison.net