
maximumeffort.substack.com
October 2, 2026
11 min read
43/100
Summary
Jev is TypeSafe’s new “System One” classifier model. The name is inspired by Daniel Kahneman’s book Thinking, Fast and Slow, in which he distinguishes between fast, instinctive, System One thinking and slower, conscious, System Two thinking.1 In this analogy, Large Language Models (LLMs) like Claude or GPT are System Two models and “Decision Models” like Jev and its predecessors (e.g. Laya) are Sy...