Senior Software Engineer, Billing - Weights & Biases

About this Role:

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 CoreWeave 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.

What You’ll Do

• 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.

Minimum Qualifications:

• 5+ years of experience building and maintaining production web applications, with strong competency across both backend and frontend systems.
• Deeply comfortable working in evolving or ambiguous systems, using pragmatic decision-making to drive progress without unnecessary rework or premature abstraction.
• Experienced with Go, React, or similar technologies, and proficient in designing clean interfaces between services, databases, and UI flows.
• Skilled at evaluating performance, reliability, and operational cost — determining when improvements materially change outcomes and when simpler solutions suffice.
• Strong communicator who collaborates effectively across teams, clarifies requirements, articulates tradeoffs, and helps align partners with different priorities.
• Thoughtful about user flows, incentive structures, and how customers perceive value and trust in usage-based products.
• Someone who brings craft and creativity to problem-solving — able to design solutions that balance engineering rigor with product agility.