---
title: "Investing in Vibrant Labs: AI Agent Simulation Infrastructure"
description: Annoucing investment in Vibrant Labs, which builds production-grade simulation and verifier-driven evaluation for long-horizon AI agents.
doc_version: "1.0"
last_updated: 2025-12-03
slug: investing-in-vibrant-labs-ai-agent-simulation
outlet: Heavybit
author: Jesse Robbins
date: 2025-12-03
url: https://www.heavybit.com/press/heavybit-welcomes-new-member-vibrant-labs
type: Article
excerpt: Annoucing investment in Vibrant Labs, which builds production-grade simulation and verifier-driven evaluation for long-horizon AI agents.
quote: "Vibrant Labs opens a new frontier in AI infrastructure: production-grade, RL-ready simulation and verifier-driven evaluation built for long-horizon agents."
quoteAuthor: Jesse Robbins
tags:
  - AI Developer Tools
  - AI Infrastructure
  - Resilience Engineering
  - Venture Capital
  - Seed Stage Investing
---

> "Vibrant Labs opens a new frontier in AI infrastructure: production-grade, RL-ready simulation and verifier-driven evaluation built for long-horizon agents."
> — Jesse Robbins

I wrote the Heavybit announcement when Vibrant Labs joined the portfolio. Shahul ES and Jithin James, the team behind [Ragas.io](https://www.ragas.io), are building production-grade simulation environments and verifier-driven evaluation for long-horizon AI agents.

The operational gap is specific. Agents take on multi-step planning and execution, and developers need safe, repeatable environments to measure and improve agent behavior before deployment. Vibrant Labs ships three pieces of infrastructure:

- RL-ready simulation worlds for training agents against realistic scenarios.
- Verifier-driven evaluation that returns explanatory feedback alongside pass-or-fail signal.
- Training pipelines that turn evaluation data back into supervision signal.

> "Vibrant Labs opens a new frontier in AI infrastructure: production-grade, RL-ready simulation and verifier-driven evaluation built for long-horizon agents."

## Also Mentioned

- Jesse Robbins (person)
- Shahul ES (person)
- Jithin James (person)
- [Heavybit](https://www.heavybit.com) (company)
- Vibrant Labs (company)
- [Ragas](https://www.ragas.io) (product)

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