Staff Software Engineer - Performance

Weights & Biases at CoreWeave

CoreWeave acquired Weights & Biases to create the most powerful end-to-end platform to develop, deploy, and iterate AI faster. CoreWeave operates 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.

What You’ll Do:

Performance Engineering at Weights & Biases ensures our systems and products scale seamlessly as usage grows. We embed performance thinking into every stage of development—diagnosing issues, designing scalable patterns, and building tools that empower every engineering team to deliver fast, efficient, and reliable experiences. Our mission is to make performance a shared responsibility across the company through data, automation, and collaboration.

About the role: 

As a Staff Engineer on the Performance Engineering team, you’ll take technical ownership of complex performance challenges across the W&B platform and infrastructure. You’ll design and lead experiments to improve system scalability and latency, develop standardized benchmarking and load testing frameworks, and drive initiatives to prevent regressions across product surfaces. You’ll collaborate closely with product, infrastructure, and SRE teams, combining deep technical expertise with a holistic understanding of system behavior. Day to day, you’ll blend investigation, architecture, and enablement—helping teams measure, understand, and continuously improve performance.

Who You Are: 

• 8+ years of experience as a software engineer, with at least 2 years focused on performance optimization, systems scalability, or observability.
  
  
• Proficiency in at least one of Go, Python, or TypeScript, with strong systems-level debugging and profiling skills.
  
  
• Deep understanding of distributed systems concepts (caching, queuing, concurrency, resource contention, etc.) and their performance implications.
  
  
• Experience designing and implementing load testing, benchmarking, or performance regression frameworks (e.g., Locust, Gatling, k6, custom solutions).
  
  
• Familiarity with metrics and tracing systems (Prometheus, Grafana, OpenTelemetry, Datadog, etc.) and performance data analysis.
  
  
• Experience integrating performance measurement into CI/CD pipelines.
  
  
• Ability to design experiments, analyze large datasets, and draw actionable conclusions.
  
  
• Proven track record of driving cross-functional technical initiatives from design through adoption.

Preferred:

• Prior experience in performance engineering or SRE at scale (e.g., supporting multi-region, high-throughput systems).
  
  
• Familiarity with frontend performance monitoring and web vitals.
  
  
• Experience building developer-facing tools or frameworks.
  
  
• Background in data systems, observability, or ML infrastructure.
• Experience contributing to open-source performance or benchmarking tools.

Wondering if you’re a good fit? We believe in investing in our people, and value candidates who can bring their own diversified experiences to our teams – even if you aren't a 100% skill or experience match. Here are a few qualities we’ve found compatible with our team. If some of this describes you, we’d love to talk. 

• You love to turn messy, complex performance problems into clear, data-backed stories that lead to concrete action.
  
  
• You’re curious about how systems behave under real-world load and enjoy building experiments that reveal what’s really happening under the hood.
  
  
• You’re an expert in transforming deep technical insights into tools and processes that empower other engineers to build faster, more reliable systems.
  
  
• You find satisfaction in long-term, cross-team collaboration — helping others succeed by embedding performance thinking into their workflows.
  
  
• You get energy from bridging theory and practice: designing scalable architectures and writing the code that proves them out.
  
  
• You care deeply about measurement, iteration, and continuous improvement — not just fixing bottlenecks, but preventing them from ever recurring.
  
  

Why Us?

We work hard, have fun, and move fast! We’re in an exciting stage of hyper-growth that you will not want to miss out on. We’re not afraid of a little chaos, and we’re constantly learning. Our team cares deeply about how we build our product and how we work together, which is represented through our core values:

• Be Curious at Your Core
• Act Like an Owner
• Empower Employees
• Deliver Best-in-Class Client Experiences
• Achieve More Together

We support and encourage an entrepreneurial outlook and independent thinking. We foster an environment that encourages collaboration and provides the opportunity to develop innovative solutions to complex problems. As we get set for takeoff, the growth opportunities within the organization are constantly expanding. You will be surrounded by some of the best talent in the industry, who will want to learn from you, too. Come join us!

The base salary range for this role is $188,000 to $275,000. The starting salary will be determined based on job-related knowledge, skills, experience, and market location. We strive for both market alignment and internal equity when determining compensation. In addition to base salary, our total rewards package includes a discretionary bonus, equity awards, and a comprehensive benefits program (all based on eligibility).