Principal Software Engineer - Models

Weights & Biases at Coreweave

CoreWeave acquired Weights & Biases to create the most powerful end-to-end platform to develop, deploy, and iterate AI faster. CoreWeave operates a growing footprint of data centers covering every region of the US and across Europe, and was ranked as one of the TIME100 most influential companies of 2024. By bringing together CoreWeave's industry-leading cloud infrastructure with the best-in-class tools AI practitioners know and love from Weights & Biases, we're setting a new standard for how AI is built, trained, and scaled.

The integration of our teams and technologies is accelerating our shared mission: to empower developers with the tools and infrastructure they need to push the boundaries of what AI can do. From experiment tracking and model optimization to high-performance training clusters, agent building, and inference at scale, we're combining forces to serve the full AI lifecycle - all in one seamless platform.

Weights & Biases has long been trusted by over 1,500 organizations - including AstraZeneca, Canva, Cohere, OpenAI, Meta, Snowflake, Square, Toyota, and Wayve - to build better models, AI agents and applications. Now, as part of CoreWeave, that impact is amplified across a broader ecosystem of AI innovators, researchers, and enterprises.

As we unite under one vision, we're looking for bold thinkers and agile builders who are excited to shape the future of AI alongside us. If you're passionate about solving complex problems at the intersection of software, hardware, and AI, there's never been a more exciting time to join our team.

What You'll Do

You will own the frontend architecture of the W&B app, the product ML researchers and engineers work in every day, and be accountable for app performance, stability and reliability.

A single page in W&B assembles data from many parts of the product, which power different product features owned by different teams. Individually those requests are all reasonable; in aggregate they contribute to increased load times and a worse experience for users. Performance here is a question of composition: what queries each page needs before it can render, what queries can add to that set, and how those boundaries hold as the product grows. You'll define those boundaries and make the calls they depend on.

This role is frontend-led but architecture-deep and organizationally wide. You'll spend time shaping other teams' designs and building consensus across boundaries, and you'll own execution of your own plans when that's what it takes to land them.

In this role you'll be responsible for the architecture, performance, and stability of the W&B Models frontend, defining the frontier of innovation for the team, and managing cross team requirements within the Models system. Some examples of what you'll do:

• Setting performance targets and driving the work that meets them, with results proven in production data
• Deciding the app's delivery and rendering architecture, including how code is delivered efficiently
• Partnering with backend and platform teams on API design, including moving work out of the client
• Proposing and driving the larger overhauls that incremental work cannot reach

Additional information

Investing in our people is one of our top priorities, and we value candidates who can bring their diversified experiences to our teams. Here are some qualities we've found compatible with our team. We'd love to talk about whether this aligns with your experience and interests and what you're excited to work on next.

Minimum Qualifications

• 8+ years building user-facing software, with deep expertise in frontend architecture and performance
• Have led the transformation of a large, long-lived React application with a focus on performance, product impact and dev experience and owned the outcome
• Strong command of React and TypeScript, with production experience in GraphQL and a modern state management approach such as Redux or Zustand, including opinions on when each is the right tool
• Real performance engineering skill: you can instrument an application, read both frontend and backend traces, determine precisely where time is going, and prove the improvement with numbers
• Solid client-side caching fundamentals, including normalization, invalidation, and the failure modes that appear at scale
• Hands-on experience with bundlers and build tooling, and clear views on code splitting and delivery tradeoffs
• Enough backend depth to design systems at a high level. You can propose a new API architecture in service of a faster client and reason about its frontend implications
• Track record of validating ideas, coordinating across engineering teams, and sequencing work that spans organizational boundaries
• An operator mindset: you measure, you ship, you follow through, and you stay close to production

Preferred Qualifications

• Experience introducing automated enforcement such as lint rules, CI gates, or performance budgets that changed engineering behavior broadly
• Background in data-dense or visualization-heavy applications where rendering cost and data volume are the core constraints
• Familiarity with observability tooling such as Datadog RUM and APM, or comparable tracing and session-replay stacks
• Working knowledge of Go or a similar backend language
• Exposure to ML, MLOps, or AI agent workflows, or genuine curiosity about the researchers and engineers who use these tools
• Experience with a highly configurable product, where the space of user and deployment settings can't be exhaustively tested

Pay and benefits

The base salary range for this role is $227,000 to $303,000. 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 compensation. In 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 we've 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.
• The benefits below reflect our US-based offerings for full-time employees; for roles in other locations, benefits vary and are shared during the hiring process.
• These include:

• 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

• California Applicants
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