Ruben Fiszel is a founder and seasoned software engineer with 11 years' experience building distributed systems, compilers, and production-grade developer tooling from Paris. As founder of Windmill he leads an open-source, self-hostable platform that turns scripts into workflows, UIs and webhooks, and contributes deep back-end improvements to the projectβs scheduler, release process and core logic. Previously he led engineering efforts to bring MPC research into production at Inpher and ran an R&D team at Palantir, combining hands-on systems programming with product-facing delivery. He works extensively in Rust and has academic roots at EPFL, Stanford and Johns Hopkins, blending rigorous research exposure with practical engineering. An active angel investor, Ruben backs startups while continuing to iterate on high-performance open-source infrastructure.
11 years of coding experience
5 years of employment as a software developer
Y Combinator
Johns Hopkins University
Master of Science Computer Science minor in Financial engineering, Master of Science Computer Science minor in Financial engineering at EPFL
Visiting Student Researcher CS EE, Visiting Student Researcher CS EE at Stanford University
Open-source developer platform to power your entire infra and turn scripts into webhooks, workflows and UIs. Fastest workflow engine (13x vs Airflow). Open-source alternative to Retool and Temporal.
Role in this project:
Back-end Developer
Contributions:880 releases, 1283 reviews, 1612 commits in 8 months
Contributions summary:Ruben primarily focused on back-end development, contributing to the improvement and maintenance of the schedule editor UX. Their work involved modifying code in various back-end files, indicating a strong focus on the internal workings of the application. The commits also show that they worked on the release process, applying automatic changes to update the version number in the codebase. Their contributions touch upon multiple internal components, including database updates and changes to core logic.
Contributions:9 commits, 2 PRs, 200 pushes in 8 days
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