Senior Engineer, Core API - W&B

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.
• Define, maintain, and scale shared backend logic across services.
• Own and improve internal schema and code generation tooling to ensure 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 executing large-scale concurrent and distributed operations.
• Collaborate 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.

PREFERRED: 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.

Qualifications

Master's degree in Computer Science, Electrical Engineering, or related field.

Experience with cloud-native technologies and container orchestration (e.g., Kubernetes).

Knowledge of distributed systems concepts, including fault tolerance, load balancing, and distributed transactions.

Experience with monitoring and logging tools (e.g., Prometheus, Grafana).

Experience with CI/CD pipelines and automation tools (e.g., Jenkins, GitLab CI).

Skills

• Proficiency in Go, Python, or a comparable backend systems language.
• Experience with cloud-native technologies and container orchestration (e.g., Kubernetes).
• Knowledge of distributed systems concepts, including fault tolerance, load balancing, and distributed transactions.
• Experience with monitoring and logging tools (e.g., Prometheus, Grafana).
• Experience with CI/CD pipelines and automation tools (e.g., Jenkins, GitLab CI).

Benefits

In addition to a competitive salary, we offer a variety of benefits to support your needs. These include:

• Medical, dental, and vision insurance - 100% paid for by CoreWeave
• Company-paid Life Insurance
• Voluntary supplemental life insurance
• Short and long-term disability insurance
• Flexible Spending Account (FSA)
• Health Savings Account (HSA)
• Tuition Reimbursement
• Able to participate in Employee Stock Purchase Program (ESPP)
• Mental Wellness Benefits through Spring Health
• Family-Forming support provided by Carrot
• Paid Parental Leave
• Flexible, full-service childcare support with Kinside
• 401(k) with a generous employer match
• Catered lunch each day in our office and data center locations
• A casual work environment
• A work culture focused on innovative disruption

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!