In this conversation, Eric Simons, founder and CEO of StackBlitz, walks through one of the fastest and most consequential pivots in modern developer tooling. After nearly seven years building deep browser infrastructure and reaching roughly $700k in ARR, the company reoriented around Bolt, effectively defining the vibe-coding category and scaling past $15M ARR in a matter of months.

We go under the hood of the WebAssembly-based architecture that lets Bolt run a full Node.js environment directly in the browser, delivering near-instant feedback and fundamentally different unit economics than cloud-hosted VMs. Eric explains the specific model breakthrough that made full-stack, one-shot app generation viable, and why this moment reordered who actually builds software inside companies.

00:00 Introduction

00:36 The 7-Year History and Pivot Point

01:01 The Original WebAssembly Vision

03:20 Near Bankruptcy: $700k ARR

10:49 Sonnet 3.5: The Vibe Coding Unlock

14:23 The $15 Million ARR Board Meeting

17:19 The Web Container/WASM Advantage

22:07 Bolt Demo: Full-Stack App from a Prompt

31:09 The Changing Role of PMs and Designers

36:23 Mitigating AI-Generated Code Security Risks

47:31 The Entrepreneurial Mindset

53:35 What Eric is Tinkering With Now

In this episode of AI Tinkerers One-Shot, Joe sits down with Andrew Baker—serial builder, former Twilio engineer, and hands-on experimenter in agentic systems—to explore the rapidly evolving frontier of browser automation and AI-driven agents.

Andrew shares how his journey began with simple scripting experiments and gradually evolved into sophisticated browser agents capable of handling complex, real-world workflows. One standout example: an airline seat selector that used browser agents to secure optimal seats for frequent flyers—highlighting both the power and the limitations of today’s tooling.

Along the way, Andrew breaks down the practical challenges builders face when working with browser agents at scale:

• Vision model accuracy and UI interpretation

• DOM complexity and brittle page structures

• Authentication hurdles and session persistence

• The real economics of running large-scale automations

The conversation then shifts to “Claude Draws,” Andrew’s playful yet technically impressive side project that brings the classic 90s app Kid Pix into the age of AI. He explains how he wired up a remote PC, streamed sound output, and carefully crafted prompts that allow Anthropic’s browser agent to control a nostalgic art application—brushes, stamps, chaos, and all. The result is both a technical deep dive and a reminder that creativity is often where agentic tooling shines most.

Joe and Andrew also zoom out to examine the broader ecosystem shaping the future of browser-native agents. They discuss why UI accessibility matters for agents, how frameworks like Stagehand and Playwright are transforming automation workflows, and why personal evaluation benchmarks are becoming essential for builders pushing these systems beyond demos and into real usage.

💡 Resources & Links

Andrew Baker: https://www.linkedin.com/in/andrewtorkbaker

AI Tinkerers: https://aitinkerers.org

Andrew’s newsletter: https://implausible.ai

What you’ll learn

• How browser automation evolved from basic scripts to autonomous agents

• Why DOM parsing, vision models, and page structure still trip up agents

• How Claude for Chrome was used to control a web-based Kid Pix experience

• The architecture behind remote execution, sound streaming, and automation hacks

• How Stagehand and Playwright support modern browser automation

• The technical, economic, and ethical considerations shaping the future of browser agents

Chapters

00:00:15 — Introduction and AI Tinkerers Community

02:49 — Twilio Origins and Browser Automation Journey

04:50 — Building the Airline Seat Selector

07:51 — Browser Agent Challenges and Vision Models

10:44 — Stagehand Framework and Browser Automation Stack

13:28 — Claude for Chrome and Authentication

16:58 — Kid Pix Origins and Demo Setup

21:33 — Technical Architecture and Playwright Tricks

29:24 — Evaluation Platform and Personal Benchmarks

37:42 — Future of Browser Agents and Web Economics

Subscribe for more conversations with the builders shaping the future of AI, automation, and agentic systems.

What happens when a lifelong tinkerer turns curiosity into two major AI companies? In this episode of AI Tinkerers One Shot, Joe talks with Lukas Biewald—founder of Weights & Biases and CrowdFlower—about how early projects like robot cars and Raspberry Pi experiments shaped his engineering mindset and entrepreneurial path.

Chapters:

00:00 — Intro & Guest Background 02:07

— Early Tinkering and CrowdFlower 03:06

— Building Robot Cars and Meeting Pete Warden 08:41

— From Tinkering to Weights & Biases 12:27

— Parenting, Vibe Coding, and Kids as Makers 21:56

— 3D Printing and Creative Play 24:25

— AI Tools, Team Structure, and Company Growth 26:43

— Agentic Coding: Opportunities and Challenges 35:40

— AI in Production: Observability and Real-World Use Cases 49:28

— The Future of AI, Fine-Tuning, and RL

https://youtu.be/S84CjOrlMcY