Sim: The Visual, End-to-End Agent Builder

Sim is building the visual, end-to-end agent builder — a platform where developers can design, test, and deploy real AI agents that work in production. Founded by Emir Karabeg and Waleed Latif, Sim grew from a small San Francisco apartment to a community of 60,000 developers and 18,000 GitHub stars, recently raising a $7M Series A. In this interview with YC’s Aaron Epstein, Emir shares how they’re building the infrastructure for the agent era, and what it takes to create AI systems that reason, retrieve, and act safely at scale. Learn more about Sim at https://www.sim.ai. Chapters: 00:00 – Building the Visual Agent Builder 00:36 – What Sim Does and Why It Matters 02:05 – From a SF Apartment to 60,000 Developers 04:20 – Finding Early Users and Product-Market Fit 07:05 – Designing an End-to-End Platform for Agents 10:30 – Powering the Open Source Agent Ecosystem 13:25 – Raising a $7M Series A 16:20 – Building Agents That Actually Work 20:10 – The Infrastructure for the Agent Era 23:40 – Advice for Builders in AI

Aaron EpsteinhostEmir Karabegguest

Nov 12, 202525mWatch on YouTube ↗

EPISODE INFO

Released: November 12, 2025
Duration: 25m
Channel: YC Root Access
Watch on YouTube: ▶ Open ↗

EPISODE DESCRIPTION

Sim is building the visual, end-to-end agent builder — a platform where developers can design, test, and deploy real AI agents that work in production. Founded by Emir Karabeg and Waleed Latif, Sim grew from a small San Francisco apartment to a community of 60,000 developers and 18,000 GitHub stars, recently raising a $7M Series A. In this interview with YC’s Aaron Epstein, Emir shares how they’re building the infrastructure for the agent era, and what it takes to create AI systems that reason, retrieve, and act safely at scale. Learn more about Sim at https://www.sim.ai. Chapters: 00:00 – Building the Visual Agent Builder 00:36 – What Sim Does and Why It Matters 02:05 – From a SF Apartment to 60,000 Developers 04:20 – Finding Early Users and Product-Market Fit 07:05 – Designing an End-to-End Platform for Agents 10:30 – Powering the Open Source Agent Ecosystem 13:25 – Raising a $7M Series A 16:20 – Building Agents That Actually Work 20:10 – The Infrastructure for the Agent Era 23:40 – Advice for Builders in AI

SPEAKERS

Aaron Epstein
host
Host of YC Root Access.
Emir Karabeg
guest
Founder of Sim.ai, a visual end-to-end platform for building AI agents/workflows.

EPISODE SUMMARY

In this episode of YC Root Access, featuring Aaron Epstein and Emir Karabeg, Sim: The Visual, End-to-End Agent Builder explores sim.ai builds Figma-like canvas for end-to-end AI agents workflows Sim.ai is a visual, AI-native agent builder that lets users create end-to-end workflows via drag-and-drop plus natural-language prompting.

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