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How Gusto’s CTO uses Claude Code to ship like a startup

Eddie Kim is the co-founder and CTO of the payroll and HR platform Gusto, which just crossed $1 billion in revenue and serves more than 500,000 small businesses. Recently he did something most CTOs don’t: he went back to writing code. With three other engineers and one designer, Eddie built Gusto Cofounder, a net-new AI product, from zero code to a tier-one launch in 10 weeks. He walks through how that team actually worked, why they threw out nearly every process, and how anyone can copy the approach. *What you’ll learn:* 1. The trash-can method: how to write, review, and delete a full PR as a product decision instead of a planning doc 2. The two-tool agent stack behind Gusto Cofounder 3. The exact “perma-Zoom” setup that replaced standups, retros, and Slack threads for 10 weeks 4. How a designer with no engineering background hit the 94th percentile for shipping code 5. The eval-first workflow Eddie uses to fix real customer bugs with Claude Code 6. How a non-technical leader can prototype an idea to win buy-in, then carry it all the way to production-quality code *Brought to you by:* Magic Patterns—Prototypes that look like your product: https://magicpatterns.com/howiai Jira Product Discovery—Prioritize with insights, build with confidence: https://atlassian.com/howiai *In this episode, we cover:* (00:00) Intro: five people, 10 weeks (02:38) The origins of Cofounder (08:32) Inside the 10-week build process (12:50) Building with no PMs (14:38) The “trash can” method (17:15) The stack architecture (19:10) Shipping to production from day one (22:03) How a designer became a top engineer (29:05) Demo: Cofounder over text and Slack (31:45) Demo: running a real payroll (36:26) Live coding with evals in Claude Code (39:39) Recap: prototype, small team, permission (43:17) Lightning round (48:44) Where to find Eddie and Cofounder *Tools referenced:* • Gusto Cofounder (early access/waitlist): https://gusto.com/cofounder • Claude Code (Anthropic): https://claude.ai/code • Cloudflare Workers: https://workers.cloudflare.com/ • Vercel AI SDK: https://sdk.vercel.ai/ • DX (engineering analytics): https://getdx.com/ • Wispr Flow (voice-to-text): https://wisprflow.ai • OpenClaw: https://openclaw.ai/ *Other references:* • Gusto (the main product, “Gusto Classic”): https://gusto.com • Mindbody (referenced as customer data source): https://www.mindbodyonline.com/ *Where to find Eddie Kim:* LinkedIn: https://www.linkedin.com/in/edawerd/ *Where to find Claire Vo:* ChatPRD: https://www.chatprd.ai/ Website: https://clairevo.com/ LinkedIn: https://www.linkedin.com/in/clairevo/ X: https://x.com/clairevo _Production and marketing by https://penname.co/._ _For inquiries about sponsoring the podcast, email jordan@penname.co._

Eddie KimguestClaire Vohost
Jun 29, 202651mWatch on YouTube ↗

At a glance

WHAT IT’S REALLY ABOUT

Gusto’s CTO ships Cofounder in 10 weeks using Claude Code

  1. Gusto Cofounder was built by four engineers and one designer in 10 weeks, going from a layover-built prototype to a tier-one launch inside Gusto.
  2. The team intentionally removed traditional process artifacts—no Jira, no specs, no Figmas, no standups—replacing them with a 24/7 perma-Zoom and extremely fast code review cycles.
  3. Product scoping happened through “build-and-decide” workflows where finished pull requests functioned as proposals, and unwanted features were routinely deleted because code generation lowered the cost of iteration.
  4. The technical architecture was deliberately simple: a Cloudflare Worker running the agent loop with Vercel AI SDK, plus in-house tools and straightforward “memory” stored as database writes.
  5. Cofounder’s user value centers on multi-channel interactions (web, SMS, Slack) and real operational workflows like payroll preparation by pulling data from systems like Google Sheets and computing business-specific rules before submitting payroll.

IDEAS WORTH REMEMBERING

5 ideas

Cutting process can be the process for zero-to-one builds.

The team moved fastest by removing meetings, specs, Jira, and even Figmas, relying on a single shared whiteboard and constant collaboration in a perma-Zoom to keep decisions synchronous and lightweight.

Use pull requests as the new PRD and scope gate.

Instead of debating hypothetical requirements, they built real, review-ready PRs and then decided whether a feature deserved to exist; if not, they closed or deleted the work with minimal sunk-cost pain.

Ship “fake” UI to production early, then breathe life into it.

The designer shipped a functional-looking but canned-response experience behind a flag, while engineers built the agent loop and data models in parallel, gradually replacing mocked behavior with real functionality without rewriting the UI.

A simple agent loop stack is often sufficient.

Cofounder ran the agent loop in a Cloudflare Worker and used Vercel AI SDK, avoiding heavy frameworks for planning/memory; “memory” was treated as a tool that writes to a database column, keeping complexity low.

Fast PR review is a force multiplier—especially with AI-generated code.

Median PR review time was ~9 minutes on the team, enabled by perma-Zoom and real-time walkthroughs; this prevents AI-assisted coding from creating unreviewed backlog and keeps quality aligned with team taste.

WORDS WORTH SAVING

5 quotes

We had no meetings, we had no tech specs, we had no Figmas, we had no Jira board where we tracked stories or tracked work. Uh, we had no standups, no retros. We had nothing.

Eddie Kim

It was, like, literally just Zoom, a lot of Claude Code tokens, and some, like, really passionate people about turning this thing in- into a reality.

Eddie Kim

We would build features, and we'd just have a discussion, like, "Does this make sense to have or not?" If it is, then, like, it would get code reviewed right then and there. And if not, like, we would just delete it.

Eddie Kim

The cost to write code is now so low that you can actually, uh, build, uh, products in, in this way and whereas I think you couldn't do that, you know, six months ago.

Eddie Kim

I think for a subset of projects, like kinda more zero to one, I think docs are absolutely dead.

Eddie Kim

10-week zero-to-one build inside a large orgNo-docs/no-PM development modelPerma-Zoom and sub-10-minute PR reviews“Trash can” method: deleting PRs and rebuilding from scratchSimple agent stack: Cloudflare Workers + Vercel AI SDKShipping to production from day one via hidden pages/feature flagsNon-engineers (designer) shipping production code with AI + mentorshipMulti-channel agent UX: SMS and SlackEvals-driven development for LLM behavior fixes

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