Senior Software Engineer, Billing

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.

As a Senior Software Engineer on the Billing team, focused on full stack development, you’ll work at the intersection of engineering, product design, and the evolving economics of AI. Billing at W&B and Core Weave spans the entire product surface — usage metering, cost transparency, customer experience, internal tooling — and touches nearly every team. In this role, your engineering judgment will influence not only how we build billing systems, but how we coordinate across teams, design shared interfaces, and evolve our product in a fast‑changing industry.

We operate in a high‑growth environment where clarity, flexibility, and thoughtful decision‑making matter. Engineers on this team support each other in shaping direction, opening doors with stakeholders, and driving meaningful improvements across the organization. If you enjoy turning ambiguous problems into elegant solutions and want the opportunity to influence both product direction and engineering practices at scale, this role offers that rare combination.

• Lead end‑to‑end development across our Go services and React applications, shaping systems that must balance correctness, flexibility, and usability for customers and internal teams.
• Bring clarity to evolving problem spaces by identifying constraints, defining practical boundaries, and aligning cross‑functional partners early and often.
• Evaluate technical debt and existing system behavior with strong judgment — knowing when to refactor, when to extend, and when to avoid premature over‑engineering based on business volatility.
• Design APIs, data models, and cross‑team interfaces that support clear contracts and enable reliable collaboration between product areas.
• Collaborate closely with product, design, finance, and engineering stakeholders to ensure technical decisions reflect real user needs and emerging business realities.
• Improve system reliability and operational maturity by identifying high‑impact risks, proposing incremental safeguards, and distinguishing between must‑haves and nice‑to‑haves for SLAs.
• Influence how engineering teams work together by modeling effective communication, offering constructive feedback, and proposing patterns that elevate shared understanding across the org.
• Help evolve developer experience and observability by shaping logging patterns, instrumentation approaches, or other lightweight frameworks that can scale across teams.

• 5+ years of experience building and maintaining production web applications, with strong competency across…