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.
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.
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.
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.
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.
gstack is for developers already using Claude Code who want to impose structure on AI-assisted work. If you ship frequently, care about review and QA discipline, and are comfortable orchestrating multiple agents, the sprint model will feel familiar. If you are looking for a one-click code generator, this is not it.
gstack is best understood as discipline for AI coding — the productivity gains come from the workflow, not from magic.