Software Engineer, Core Open-Source- Marimo
Senior Software Engineer role at CoreWeave, focusing on core open-source development, leveraging expertise in AI, cloud infrastructure, and technical innovation.
CoreWeave is The Essential Cloud for AI™. Built for pioneers by pioneers, CoreWeave delivers a platform of technology, tools, and teams that enables innovators to build and scale AI with confidence. Trusted by leading AI labs, startups, and global enterprises, CoreWeave combines superior infrastructure performance with deep technical expertise to accelerate breakthroughs and turn compute into capability. Founded in 2017, CoreWeave became a publicly traded company (Nasdaq: CRWV) in March 2025. Learn more at www.coreweave.com .
About Marimo:
At Marimo , we’re on a mission to make the world’s best open-source programming environment for working with data, together with a world-class, scalable, and performant cloud-hosted counterpart. marimo is a reinvention of the Python notebook — it feels like a next-gen reactive Python notebook, but is stored as pure Python that can be versioned with Git, deployed as a data app, run as a script, and reused as a module. Incubated initially with scientists at Stanford, marimo is now used by leading companies, labs, and universities around the world, with millions of downloads since launch and over 17,000 stars on our GitHub repository .
On the Marimo team, we believe that the tools we use shape the way we think — better tools, for better minds. If you're passionate about developer tools, thrive in ambiguity, enjoy solving challenging engineering problems at scale, and yearn for greenfield problems, you'll fit right in.
About the Team:
The Marimo core open source team develops and maintains the marimo open source notebook. Today, this includes the marimo editor frontend, the marimo backend which includes the core dataflow compiler and runtime, an intermediary server, the marimo library, and an ecosystem of related projects, such as a VS Code extension, codemirror extensions, and more. This team has the crucial role of shepherding the future of one of Python's fastest growing and most impactful open-source projects.
About the Role:
As a Senior Software Engineer on Marimo's core open source team, you’ll take ownership of projects across Marimo's open-source ecosystem, focusing on Marimo's backend and its Python ecosystem. You will influence critical decisions on library design, making sure our APIs remain simple yet composable; you'll also design new capabilities that push the boundaries of interactive computing without complicating the user experience. You'll work in the open, at a fast pace — engaging promptly and empathetically with a large and vocal community of users and contributors, triaging their issues and reading between the lines to understand their unstated needs. All the while, you'll exercise judgment to balance the needs of our community with our own roadmap and vision.
Who You Are:
Posted June 6, 2026