Open-source platform to build internal apps, from minimal scripts

Founding Engineer

$70k - $110k / 0.25% - 2.00%
Paris, France / Remote
Job Type
Any (new grads ok)
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Ruben Fiszel
Ruben Fiszel

About the role

We are a small but mighty team and compete with well-funded proprietary alternatives. As such, we need to make fast-paced, iterative and sustainable software design choices. You can find more information about our architecture in the documentation but overall is both a flow builder platform based on minimal scripts, and a highly available compute providers, built with rust, postgres, sandboxing (nsjail) and svelte for the frontend. You will work autonomously but in highly collaborative setting as an engineer to make a delightful, scalable and performant product.

A large part of business is its hosted SaaS part which implies that we must ensure high availability in the software and the infrastructure choices that we make and in the SLA that we offers. As a founding DevOps engineer, you will ensure that we make the right choices in terms of observability, incident responses, software design, high-availability and infrastructure.'s current architecture design is stateless replicated rust servers backed by postgres instances sharded by workspaces id. We use Hetzner Cloud for cost purposes and run on top of nomad for deployment state management.

About the interview

  1. Intro call with Founder, to do a quick eval if there is a mutual fit, we also talk about logistics there (remote, location, visas, etc) (30 min)
  2. Intro call with the team: This is a team game, everyone must feel comfortable working with you (and mutually) (30 min)
  3. You get familiar with the Windmill codebase and architecture available on the Github repo, you ping us once ready
  4. You tell us about ideas and features you would be excited to work on and we discuss how you would implement it from high-level to low-level details (2h)

Why you should join Windmill

Windmill ( is an open-source & self-hostable developer platform for multi-step automation & internal tools. It is an open-source ( alternative to and pipedream. It allows for building flows from minimal and normal looking scripts in python and typescript. It is similar to no-code tools except that each module is a script underneath. The conversion from script to a blackbox module is done automatically through static analysis of the main function parameters. Scripts are shared on WindmillHub ( It embeds a serverless worker and can be seen as an all-in-one Flow builder + FaaS (Function-as-a-Service = Task queue + Worker).

In addition the platform provides automatic generation of the triggering UI per-script and per-flow, cron scheduling, separation of credentials and logic, versioning, importing scripts from Github and more.

There are two modes of triggering for each flow:

  • Triggered by an external event, either listening for changes or being triggered through a Webhook
  • Triggered manually through an automatically generated form that corresponds to the flow or script input.

The main insight is that available no-code tools today are intuitive for non-technical users but lacks the extensibility that scripting provide. On the other hand, scripting is very powerful but writing a script is only 10% of the work. You then have to deal with getting credentials, separate sensitive values, deploy your script, handle permissions, build a UI, handle errors and so on. Windmill combines the best of both world.

The vision is to become the ubiquitous tool for all operation, internal tool, integration and automation of all org. Most companies are becoming tech companies or tech empowered. The tech stack of any company is usually as follows:

  • Product (Frontend + Backend): Here Supabase/Firebase provides Backend-as-a-Service so you can focus on building your custom logic and your product's UI
  • Ops: Custom Business-Logic + Backend + Frontend: Here Windmill enables you to focus on your custom business logic and avoid having to reinvent the wheel, by providing the generic backend + frontend.

Hence Windmill is a platform and infrastructure layer that lowers the barrier to entry to become a tech company, by allowing anyone to focus on their script/business logic and not the infra on which they run upon.

Team Size:2
Location:Paris, France
Ruben Fiszel
Ruben Fiszel