gstack: Garry Tan ships code 810x faster with 23 AI agents

The CEO of Y Combinator claims he ships code 810 times faster than he did in 2013 — not by typing faster, but by running 23 AI agents in parallel. The tool he uses is open source.

What it is

gstack is an open source software factory for Claude Code. It packages 23 specialist skills and 8 power tools as slash commands, turning a single coding agent into a structured team: a CEO that reviews product, an engineering manager that locks architecture, a designer that catches AI slop, a reviewer that finds bugs, a QA lead that opens a real browser, and a security role that runs OWASP scans.

The framing is deliberate. gstack is not a magic button and it does not replace understanding code. It is a workflow enforcement layer — a way to make AI coding follow a disciplined sprint instead of generating undifferentiated slop. Garry Tan reportedly shipped 3 production services and over 40 features in 60 days, part-time, using this approach.

Why it matters

• One person can operate like a team of 20, provided they know the tools. The sprint structure — think, plan, build, review, test, ship, reflect — means nothing falls through the cracks.
• QA is the biggest unlock. The agent opens a real Chromium browser, performs real clicks, takes real screenshots, finds a bug, fixes it, and generates a regression test. That is what reportedly let Tan scale from 6 to 12 parallel workers.
• Security runs OWASP scans, so the output is closer to production-ready than raw agent output.
• It is MIT licensed, free, and open source. No vendor lock-in, no per-seat pricing.

How it works

The unit of work is a sprint. It starts with /office-hours to write a design doc, moves through /plan-ceo for a CEO-level review, then /build implements, /review finds bugs, and /ship sends the PR. Each slash command invokes a specialist role with its own prompt and acceptance criteria.

The parallelism comes from a separate Conductor tool that lets you run 10 to 15 sprints at once — brainstorming an idea, reviewing a PR, QA-ing staging, implementing a feature — managed the way a CEO manages a team. The 810x headline comes from comparing 11,417 logical lines of change per day in 2026 against 14 lines per day in 2013.

Caveats

The 810x figure measures logical code change, not raw lines of code, and it reflects Garry Tan's own methodology — not a benchmark you will reproduce by installing the tool. gstack requires a Claude Code subscription, which runs $100 or more per month, plus Bun and Git. There is a learning curve: 23 skills take time to internalize, and parallel sprints need the separate Conductor tool. It is a workflow system, not an autopilot.

Who it's for