Windmill YC Application

Summer 2022Active

Windmill went through Y Combinator in the Summer 2022 batch as a B2B company. Below: what the company does, who founded it, and its application to YC, reconstructed question by question in the real YC form.

YC batch: Summer 2022
Industry: B2BInfrastructure
Team size: 7
Status: Active
Launched: 2022

Founders

Ruben FiszelFounder

What Windmill does

Windmill is an open-source developer platform that turns scripts into workflows, internal tools, and full-stack apps. Write scripts in Python, TypeScript, Go, Bash, Rust, SQL - Windmill auto-generates UIs from their parameters, handles dependencies, credentials, permissions, and scheduling so you focus on business logic, not infra. Open-source alternative to Airflow, Temporal, Retool and n8n. Chain scripts into flows with branching, parallelism, retries. Build dashboards with the app builder. Trigger via cron, webhook, or UI. All-in-one runtime, editor, secret manager, and OAuth platform - enterprise-ready out of the box. Stack: Rust / TypeScript + Svelte / PostgreSQL. Self-hostable, easy to deploy, built for performance and DX.

Windmill's YC application, reconstructed

Y Combinator application

Windmill, Summer 2022 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

Windmill

Describe what your company does in 50 characters or less.

Open-source platform to turn scripts into internal apps

What is your company going to make? Please describe your product and what it does or will do.

We build an open-source developer platform that turns scripts written in languages like Python, TypeScript, Go, Bash, Rust, and SQL into internal tools and workflows with autogenerated UIs. Our platform handles dependencies, credentials, permissions, scheduling, and provides branching and retries, so developers focus on business logic instead of infrastructure. It's a self-hostable alternative to tools like Airflow or Retool with a runtime, editor, secret manager, and OAuth built in.

Where do you live now, and where would the company be based after YC?

We live and work in Paris, Île-de-France, France. After YC, we plan to keep the company based here.

Explain your decision regarding location.

We chose Paris because it's where we live and where the core team is. We can recruit locally and work remotely but want to maintain our base here to keep strong focus and momentum.

21 more answers in the full application

Founders, Progress, Idea, Equity, Curious, Batch Preference are in the full version. Create a free account to open it in YC Insights, next to every other YC batch.

See full application

Frequently Asked Questions

Is this the real Windmill YC application?

No. Y Combinator keeps submitted applications private. This is a reconstruction: the real YC form questions, answered from Windmill's public data (launch notes, founder backgrounds, product description). It shows how a company like Windmill would present itself to YC, not the text they submitted.