Senior Software Engineer, Mobile (iOS)

Overview

Core Weave, the AI Hyperscaler™, acquired Weights & Biases to create the most powerful end-to-end platform to develop, deploy, and iterate AI faster. Since 2017, Core Weave has operated a growing footprint of data centers covering every region of the US and across Europe, and was ranked as one of the TIME 100 most influential companies of 2024. By bringing together Core Weave’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 Core Weave, 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 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.

The Role

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 Graph QL APIs. The codebase is modern Swift 6 and Swift UI 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 entry points beyond work spaces 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.

Who You Are

• 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 Graph QL 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 (Git Hub Actions, Circle CI, or similar)

Preferred

• Experience with ML tools, developer tools, or data-intensive applications
• Familiarity with Tuist or similar build system tooling for modular iOS projects
• Experience with…