Senior Software Engineer, Core Open-Source

CoreWeave

Senior Software Engineer on Marimo's core open source team, driving backend development and library design. Engaging with a vibrant community to enhance a pioneering data tool.

Posted 6/2/2026full-timeRemote • California, New Jersey, New York, Washington • 🇺🇸 United StatesSenior💰 $165,000 - $242,000 per yearWebsite

Tech Stack

Tools & technologies

PythonRustSQLTypeScript

About the role

Key responsibilities & impact

Take ownership of projects across Marimo's open-source ecosystem, focusing on Marimo's backend and its Python ecosystem
Influence critical decisions on library design, ensuring APIs remain simple yet composable
Design new capabilities that push the boundaries of interactive computing without complicating user experience
Work in the open, at a fast pace — engage promptly with a large and vocal community of users and contributors
Triaging issues and reading between the lines to understand unstated needs
Exercise judgment to balance the needs of community with roadmap and vision

Requirements

What you’ll need

4+ years of experience in software engineering
Proficiency in Python, with strong fundamentals that are language agnostic
Proficiency in computer systems, including parallel computing (threading, multiprocessing), concurrency (asynchronous programming), basic networking/inter-process communication
Experience in library design and/or open-source development
Strong communication skills, written and verbal.
A passion for and experience building developer tools, especially for AI, ML, or data (preferred)
A passion for working with data, with the ability to empathize with practitioners and researchers in AI, ML, data engineering, NLP, or other quantitative work (preferred)
An eye for visual and interaction design, with an emphasis on simplicity (preferred)
You find enjoyment in connecting with users and community daily (preferred)
Proficiency in Typescript, or a willingness to learn (preferred)
Experience with AI engineering, including MCP and agents (preferred)
Experience with SQL, databases, and data engineering (preferred)
Experience with at least one systems language, such as C or Rust (preferred)

Benefits

Comp & perks

Medical, dental, and vision insurance - 100% paid for by CoreWeave
Company-paid Life Insurance
Voluntary supplemental life insurance
Short and long-term disability insurance
Flexible Spending Account
Health Savings Account
Tuition Reimbursement
Ability to Participate in Employee Stock Purchase Program (ESPP)
Mental Wellness Benefits through Spring Health
Family-Forming support provided by Carrot
Paid Parental Leave
Flexible, full-service childcare support with Kinside
401(k) with a generous employer match
Flexible PTO
Catered lunch each day in our office and data center locations
A casual work environment
A work culture focused on innovative disruption

ATS Keywords

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Hard Skills & Tools

Pythoncomputer systemsparallel computingconcurrencyasynchronous programminglibrary designopen-source developmentTypescriptSQLdata engineering

Soft Skills

strong communication skillsempathyenjoyment in connecting with usersjudgmentability to triage issues