---
id: "entity-claude-3-5-sonnet"
type: "entity"
entityType: "product"
canonicalName: "Claude 3.5 Sonnet"
aliases: ["Sonnet 3.5", "Claude Sonnet 3.5"]
source_timestamps: ["00:07:40"]
tags: ["llm", "coding-models"]
related: ["entity-anthropic", "entity-strongdm"]
url: "https://www.anthropic.com/claude/sonnet"
sources: ["s01-5-levels-ai-coding"]
sourceVaultSlug: "s01-5-levels-ai-coding"
originDay: 1
---
# Claude 3.5 Sonnet

## Profile
A frontier AI model released by [[entity-anthropic-d1|Anthropic]] in the fall of 2024.

## Significance
The speaker identifies the release of Claude 3.5 Sonnet as the **inflection point** at which **long-horizon agentic coding started compounding correctness rather than compounding errors**. Before this release, agents tended to drift; after, they were able to chain reasoning across long-running tasks reliably enough to support production-grade autonomous workflows.

## In-Vault Usage
- Powers the [[entity-strongdm|StrongDM]] [[concept-dark-factory|Dark Factory]] alongside the open-source *Attractor* agent.
- Cited as the enabling technology for moving past Level 3 toward Levels 4 and 5 of the [[framework-5-levels-vibe-coding|5 Levels framework]].