Office hours with Gstack.
The interview before you build.

Built by Garry Tan, President of Y Combinator

Describe your product idea. Gstack will pressure-test it the way
Y Combinator partners do — identifying demand, status quo, and wedge.

Hosted on Lightsprint

“The absolute fastest way to try gstack.”

Garry Tan, President of Y Combinator

Garry shipped 10,000 lines of code and 100 pull requests a week using gstack.
Now your team can run the same workflow, together, in the cloud.

What is gstack

Six reviewers. One airtight plan.

gstack models a startup sprint end-to-end: rethink the product as a CEO,
plan the architecture as an engineer, review with a designer's eye…
When ready, build with Lightsprint cloud agents and ship with confidence.

Reviewer 1

Garry Tan

The YC President's lens. Pressure-tests demand, status quo, and your wedge. Forces evidence — not hypotheses — before any code is written.

🏆

Reviewer 2

CEO

Challenges scope and premise. Decides what gets cut, what gets held, what gets selectively expanded.

🛠️

Reviewer 3

Engineer

Calls out architecture risk, edge cases, and test strategy. The eng-lens review every plan must survive.

🎨

Reviewer 4

Designer

Surfaces UX gaps and visual debt before they ship. The design-lens review with bite.

🚀

Reviewer 5

DevEx

Checks shipability and maintainability. Will the next engineer be able to read this in six months?

🔎

Reviewer 6

QA

Runs the build with live preview environments, catches regressions, and verifies edge cases before anything touches production.

Sample question

No Skip Button. No Hand-Waving.

Concrete, evidence-demanding questions. Your hypothesis either survives office hours — or doesn't deserve a spec yet.

Demand gstack · autoplan · phase 1 Question 2 of 3

Let's explore customer demand. Show three recent moments when a teammate or customer needed an answer that was already buried in a Slack thread, Notion page, or customer call. What would they have searched for in your proposed AI-powered wiki product?

A Found three: CS searched Slack for SSO context, sales needed a pricing answer from a customer call, and engineering re-asked a setup question already documented in Notion.

B I can find one Slack thread, but the Notion and customer-call examples are guesses. We don't yet have enough evidence that people need a shared brain for this.

Forcing function: demand — the wizard expects a concrete answer, not a hypothesis. There's no "skip" button.

Lightsprint is backed by Y Combinator and powers gstack for teams building in production.

☁️

Cloud-native execution

No local Claude Code setup, no API keys to manage, no compute constraints. Agents run in isolated cloud environments on your real codebase.

👥

Built for teams

gstack locally is single-player. On Lightsprint, your whole team sees every phase, reviews plans together, and ships from one shared workspace.

👁️

Live preview for every change

Every build phase gets its own live URL. Click through changes like a user before they touch production. QA phase tests it automatically.

Your team's gstack is ready.

Connect your repo. Run Think, Plan, Build, Review, QA, Ship. Collaborate with your team at every step. Start free — no credit card, no local setup.

Start free Book a demo

Office hours with Gstack. The interview before you build.