Yesterday two Amazon engineers published a post with a headline built for Hacker News: Amazon saves millions by replacing Sonnet 4.6 with Strands Decider . By this morning it had hundreds of points and a very opinionated comment thread .

I've led teams for years and shipped a fair number of startups, some of which are no longer with us. This story touches a habit I recognize in myself, so I want to go through what they actually did, why it worked, and why I'm not fully convinced yet.

What happened

Amazon has a huge internal ticketing system covering customer escalations, capacity requests, alarms and security findings. Every ticket needs one of 20 labels. That job was done by Claude Sonnet 4.6, a large and capable language model.

They replaced it with Strands Decider , a "decision model" Amazon launched about a month ago. It can't generate text. You give it some state (the ticket), a question and a list of options. It returns a probability for each option plus a confidence score.…