A virtual product team, in your browser
Turn a rough idea into a sharper plan
gstack is a set of expert AI playbooks created by Y Combinator CEO Garry Tan. It asks the hard questions a CEO, engineer, and designer would ask—then gives you a concrete next step. gstackweb puts those workflows in your browser, with no coding knowledge required.
Runs the original /office-hours workflow. No terminal or setup.
120K+
GitHub stars
18K+
GitHub forks
23
specialist workflows in original gstack
MIT
open-source license
Why people pay attention to gstack
Garry Tan is President & CEO of Y Combinator. The original project says he uses gstack daily and built it from workflows refined over 20 years of product work.
What it actually does
A product team's questions, packaged into repeatable AI workflows
A blank AI chat often agrees too easily. gstack gives the AI a specific job, a sequence of questions, and a standard for a useful answer.
A tough idea check
Structured questions expose whether the problem is real, who cares, and what the smallest useful version should be.
An expert second opinion
Switch between CEO, engineering, and design perspectives instead of hoping one generic AI chat catches everything.
A decision you can use
Each run ends with a clearer concept, a verdict, priorities, or concrete next actions—not just more conversation.
Six workflows available now
Choose the question you need answered
/office-hours · Office Hours
Is this idea worth building?
Answer six hard questions about the problem, customer, and smallest useful version. Get a refined idea, grade, and homework.
Pressure-test my idea →
/plan-ceo-review · CEO Plan Review
What should I build—and cut?
Get a clear expand, keep, pause, or reduce verdict so you can focus time and money on the parts that matter.
Review my plan →
/plan-eng-review · Engineering Plan Review
Will this plan actually work?
Find missing steps, risky assumptions, edge cases, and testing gaps before they become expensive problems.
Check feasibility →
/plan-design-review · Design Plan Review
What would make this design stronger?
Score the important parts of a design from 0–10 and see exactly what would move each one closer to 10.
Review my design →
/design-consultation · Design Consultation
How should this product look and feel?
Turn a rough brief into a concrete direction for color, type, layout, motion, and overall product feel.
Create a direction →
/design-shotgun · Design Shotgun
Show me several directions
Generate different design approaches side by side so you can compare before committing to one.
Explore directions →
How it works
Bring the messy version
You do not need a finished business plan, design brief, or technical document to start.
Choose the decision you need help with
Start with your idea, product plan, technical plan, or design.
Explain it in plain language
No special format or technical knowledge is required.
Answer the guided questions
The selected gstack workflow challenges assumptions from its specialist perspective.
Leave with a clearer decision
Use the verdict, priorities, and next actions in your real work.
The original gstack lives inside developer software.
gstackweb brings the same structured playbooks to a normal browser, so people with ideas—not just developers—can use them.
gstackweb Pro
10 guided gstack reviews every month
Use Office Hours, CEO, Engineering, and Design workflows whenever a decision needs a serious second opinion. Pro also includes private results, saved history, and follow-up emails.
Get 10 reviews — $19/month