Senior Software Engineer, Core API - Weights & Biases

About the role

The Core Systems team is responsible for the foundational backend infrastructure that powers Weights & Biases within CoreWeave. Much of the platform's critical logic is shared across services, and this role sits at the center of that foundation.

Responsibilities

• Build and evolve the core backend systems and shared infrastructure that power our platform.
• A significant portion of backend logic is shared across services, and this role will help define, maintain, and scale that foundation.
• Own and improve internal schema and code generation tooling that ensures consistency and correctness across services.
• Work on and extend our custom job scheduler, improving reliability, observability, and execution guarantees for distributed workloads.
• Contribute to safely execute large-scale concurrent and distributed operations.
• Collaborate closely with Product and various Engineering teams to design systems that are reliable, scalable, and maintainable over time.
• Define and maintain API standards across teams, ensuring performance, backward compatibility, and clear evolution strategies.

Requirements

• 5+ years of backend engineering experience building and operating production systems.
• Proven experience designing and maintaining distributed systems at scale.
• Hands-on experience designing and evolving APIs (REST, GraphQL, and/or gRPC).
• Strong proficiency in Go, Python, or a comparable backend systems language.
• Experience implementing concurrency and parallelism patterns in production systems.
• Demonstrated ownership of shared infrastructure, internal platforms, or developer tooling used by multiple teams.
• Experience diagnosing and optimizing system performance, including CPU, memory, I/O, and network bottlenecks.

Qualifications

• Familiarity with schema management, code generation tools, or interface definition systems (e.g., protobuf, OpenAPI, GraphQL schemas).
• Experience building or operating custom job schedulers, workflow engines, or execution frameworks.
• Experience defining cross-team API standards and governance models.
• Background in high-scale data or ML infrastructure systems.
• Experience improving reliability through observability, metrics, and SLO-driven development practices.

Skills

• Strong understanding of cloud infrastructure and services.
• Experience with containerization and orchestration tools (e.g., Kubernetes).
• Knowledge of microservices architecture and design principles.
• Experience with monitoring and logging tools (e.g., Prometheus, Grafana).
• Understanding of security best practices and compliance requirements.

Benefits

CoreWeave offers a comprehensive benefits program including medical, dental, and vision insurance, company-paid life insurance, short and long-term disability insurance, a flexible spending account, a health savings account, tuition reimbursement, a mental wellness benefit, a family-forming support program, a parental leave policy, childcare support, a 401(k) with a generous employer match, and a variety of additional perks.

Pay

The base salary range for this role is $165,000 to $242,000. The starting salary will be determined based on job-related knowledge, skills, experience, and market location.

Schedule

CoreWeave operates on a standard 9-to-5 schedule with occasional evening and weekend work as needed.