Senior Software Engineer, Core Open-Source- Weights & Biases

San Francisco, CA - USA

Monthly Salary: $ 165000 - 242000

Posted on: 17 hours ago

Vacancies: 1 Vacancy

Job Summary

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.

What Youll Do:

What is marimo

At marimo were on a mission to make the worlds 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 17000 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 youre passionate about developer tools thrive in ambiguity enjoy solving challenging engineering problems at scale and yearn for greenfield problems youll fit right in.

Description of 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 Pythons fastest growing and most impactful open-source projects.

About the role:

As a senior software engineer on marimos core open source team youll take ownership of projects across marimos open-source ecosystem focusing on marimos backend and its Python ecosystem. You will influence critical decisions on library design making sure our APIs remain simple yet composable; youll also design new capabilities that push the boundaries of interactive computing without complicating the user experience. Youll 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 youll exercise judgment to balance the needs of our community with our own roadmap and vision.

Who You Are:

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

Preferred:

A passion for and experience building developer tools especially for AI ML or data
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
An eye for visual and interaction design with an emphasis on simplicity
You find enjoyment in connecting with users and community daily
Proficiency in Typescript or a willingness to learn
Experience with AI engineering including MCP and agents
Experience with SQL databases and data engineering
Experience with at least one systems language such as C or Rust

Wondering if youre a good fit We believe in investing in our people and value candidates who can bring their own diversified experiences to our teams even if you arent a 100% skill or experience match. Here are a few qualities weve found compatible with our team. If some of this describes you wed love to talk.

You love crafting developer tools especially for AI ML or data
Youre curious about the day-to-day work of AI/ML/data engineers researchers and scientists
You enjoy building in the open and engaging with your users

The base salary range for this role is $165000 to $242000. The starting salary will be determined based on job-related knowledge skills experience and market location. We strive for both market alignment and internal equity when determining addition to base salary our total rewards package includes a discretionary bonus equity awards and a comprehensive benefits program (all based on eligibility).

What We Offer

The range weve posted represents the typical compensation range for this role. To determine actual compensation we review the market rate for each candidate which can include a variety of factors. These include qualifications experience interview performance and location.

In addition to a competitive salary we offer a variety of benefits to support your needs including:

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

Our Workplace

While we prioritize a hybrid work environment remote work may be considered for candidates located more than 30 miles from an office based on role requirements for specialized skill sets. New hires will be invited to attend onboarding at one of our hubs within their first month. Teams also gather quarterly to support collaboration

California Consumer Privacy Act - California applicants only

CoreWeave is an equal opportunity employer committed to fostering an inclusive and supportive workplace. All qualified applicants and candidates will receive consideration for employment without regard to race color religion sex disability age sexual orientation gender identity national origin veteran status or genetic information.

As part of this commitment and consistent with the Americans with Disabilities Act (ADA) CoreWeave will ensure that qualified applicants and candidates with disabilities are provided reasonable accommodations for the hiring process unless such accommodation would cause an undue hardship. If reasonable accommodation is needed please contact: .

Export Control Compliance

This position requires access to export controlled information. To conform to U.S. Government export regulations applicable to that information applicant must either be (A) a U.S. person defined as a (i) U.S. citizen or national (ii) U.S. lawful permanent resident (green card holder) (iii) refugee under 8 U.S.C. 1157 or (iv) asylee under 8 U.S.C. 1158 (B) eligible to access the export controlled information without a required export authorization or (C) eligible and reasonably likely to obtain the required export authorization from the applicable U.S. government agency. CoreWeave may for legitimate business reasons decline to pursue any export licensing process.

Required Experience:

Senior IC