Principal Software Engineer (Models)

Join our team as a Principal Software Engineer (Models) and take ownership of the frontend architecture of the W&B app. You will be responsible for app performance, stability, and reliability, and will work closely with other teams to shape designs and build consensus. This role requires a deep understanding of frontend architecture and performance, as well as experience in coordinating across engineering teams and sequencing work that spans organizational boundaries.

- 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
- 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
- Solid client-side caching fundamentals, including normalization, invalidation, and the failure modes that appear at scale
- 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
- 8+ years building user-facing software, with deep expertise in frontend architecture and performance
- 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
- 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