---
id: "entity-org-third-layer"
type: "entity"
entityType: "organization"
canonicalName: "Third Layer"
aliases: []
source_timestamps: ["00:00:34", "00:00:40"]
tags: ["startup", "y-combinator", "yc-w24"]
related: ["concept-meta-task-agent-split", "concept-harness-engineering"]
url: "https://thirdlayer.io/"
sources: ["s04-karpathy-agent-700"]
sourceVaultSlug: "s04-karpathy-agent-700"
originDay: 4
---
# Third Layer

## Profile
A small **Y Combinator W24** AI startup that applied the [[concept-karpathy-loop|Karpathy Loop]] pattern to agentic harnesses, demonstrating that small teams can achieve state-of-the-art results using auto-optimization.

## Role in the Source
Cited as a productization example: the [[concept-meta-task-agent-split|Meta/Task split]] applied to agentic [[concept-harness-engineering|harness]] tuning at small-team scale.

## Strategic Significance
Third Layer is a concrete instance of the [[claim-small-teams-advantage|small-teams asymmetric advantage]] — a YC-stage team competing with much larger AI shops by leveraging auto-optimization.

## Canonical Reference
- https://thirdlayer.io/