Senior Software Engineer I, Mobile (iOS)- Weights & Biases

Weights & Biases•Sunnyvale, CA

4d•$139,000 - $204,000•Hybrid

About The Position

CoreWeave, the AI Hyperscaler™, acquired Weights & Biases to create the most powerful end-to-end platform to develop, deploy, and iterate AI faster. Since 2017, CoreWeave has operated 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. You'll be joining the Mobile team within the ML Workflows organization. We recently launched the W&B iOS app at NVIDIA GTC 2026, bringing run monitoring, project browsing, metric visualization, and push notifications to ML practitioners on the go. The app is live on the App Store and already seeing adoption across research labs, universities, and AI companies. We're now building on that momentum to expand the mobile experience and make W&B the app ML engineers check first when they want to know how their training runs are going. As a Senior Engineer on the Mobile team, you'll be one of the first engineers shaping the future of W&B's mobile experience. Your day-to-day will involve building new iOS features end-to-end, from the data layer through shipping to the App Store. You'll work on charting and data visualization for ML metrics, real-time notifications, offline support, and deeper integrations with the W&B platform via GraphQL APIs. The codebase is modern Swift 6 and SwiftUI with a clean modular architecture, and you'll have significant influence over technical direction as the team grows. You'll work closely with a dedicated designer, product manager, and one other full-time engineer, and collaborate with backend engineers across multiple W&B product areas. Mobile is becoming the surface for a broad set of W&B entrypoints beyond workspaces and visualization, and you'll be building across all of them. Like any role at a hyperscaler, this comes with high accountability and ownership. You'll own the features you build from design through production, and you'll care deeply about the experience ML practitioners have with the app every day.

Requirements

4+ years of professional iOS development experience
Strong proficiency in Swift and SwiftUI
Experience shipping and maintaining apps on the App Store
Experience using and maintaining mobile design systems
Solid understanding of iOS app architecture patterns (MVVM, dependency injection, modular codebases)
Experience with GraphQL or RESTful API integration in mobile apps
Experience with push notifications (APNs, Firebase/FCM)
Strong focus on writing clean, well-tested, and maintainable code
Comfortable working in a small team with high autonomy and direct impact on product direction
Experience with CI/CD pipelines for iOS (GitHub Actions, CircleCI, or similar)

Nice To Haves

Experience with ML tools, developer tools, or data-intensive applications
Familiarity with Tuist or similar build system tooling for modular iOS projects
Experience with observability and logging in mobile apps (Datadog, Sentry, or similar)
Background in building real-time or near-real-time data display on mobile
Familiarity with data visualization and charting on iOS (Swift Charts or similar)
Experience with product analytics instrumentation (Segment, Amplitude, or similar)
Knowledge of Auth0 or similar authentication frameworks on iOS
Experience with accessibility and internationalization on iOS
Previous work on apps used by technical or developer audiences