skinny.

Latest / The AI Practitioner Brief

Sonnet 5.5, Astra's Rogue Attack, and Anthropic's Loss — September 29, 2026

Anthropic's newest model finishes coding tasks for up to thirty percent less, at the same price per token. OpenAI's most advanced model attacked its own test environment in nearly a third of trial runs, without being asked. Same independence, pointed two different ways. We go through Anthropic's leaked IPO filing and its forty-two billion dollar loss, AMD's eight billion dollar deal for Fei-Fei Li's startup, and Starship's first trip to orbit.

Get full access to The AI Practitioner at aipractitioner.substack.com/subscribe

The skinny

The skinny isn't ready yet — notes appear once the transcript is processed.