Senior Software Engineer, W&B Agent - W&B

Quick Facts

• Senior Full Stack Engineer on the ARIA Agent team (AI Research and Iterations Agent)
• Own features across backend infrastructure/API design and React frontend

Description

Build the ARIA AI Research and Iterations Agent enabling continuous experimentation at scale. The engineering team creates a distributed, agent-driven system end to end—from backend infrastructure executing multi-turn agent conversations to a React UI used daily by ML practitioners.

Responsibilities

• Build ARIA from scratch using distributed backend systems for multi-turn agent conversations
• Ship a fast, reliable, and delightful agent experience that accelerates ML workflows
• Design and maintain distributed worker systems running agent conversations at scale
• Design streaming architecture for real-time token output to the browser
• Contribute to frontend components for chat interface, billing UI, and agent configuration experience
• Collaborate with ML science, product, iOS, and SRE teams with a blend of reliability engineering and product sensibility
• Debug and harden production systems (e.g., memory leaks in Kubernetes workers)
• Harden security controls on the code execution sandbox (e.g., egress controls)

Requirements

• 4+ years of full stack engineering experience with depth in backend services and React/TypeScript frontend development
• Strong Python backend skills: async patterns, FastAPI, distributed state machines, Kubernetes pod lifecycle
• Proficient in TypeScript and React; ability to build and maintain production UI components including real-time streaming interfaces, complex state management, and responsive layouts across web and mobile web
• Experience building and operating services at scale: rolling deploys, autoscaling, worker concurrency, graceful termination
• Experience with observability tooling (Datadog, Weave tracing, structured logging) and building actionable dashboards
• Security-conscious engineering mindset: input validation, sandboxed code execution, egress controls, payload hardening
• Experience with MySQL or similar RDBMS for transactional state management

Preferred

• Streaming UI experience (server-sent events, WebSockets) with graceful fallback handling
• Background in ML infrastructure, developer tooling, or observability platforms
• Hands-on experience shipping production AI agents (tool use, multi-turn management, agentic reliability patterns)
• Thrives in a fast-paced startup environment; can iterate from user feedback without sacrificing production quality

Benefits

• Base salary range: $182,000 to $242,000 (starting salary based on job-related knowledge, skills, experience, and market location)
• Discretionary bonus and equity awards
• Medical, dental, and vision insurance: 100% paid
• Company-paid life insurance; voluntary supplemental life insurance
• Short and long-term disability insurance
• Flexible Spending Account; Health Savings Account
• Tuition Reimbursement
• Employee Stock Purchase Program (ESPP)
• Mental wellness benefits through Spring Health
• Family-forming support (Carrot)
• Paid Parental Leave
• Flexible, full-service childcare support (Kinside)
• 401(k) with generous employer match
• Flexible PTO
• Catered lunch each day in office and data center locations
• Casual work environment; culture focused on innovative disruption

Other

Requires access to export controlled information; applicants must be a U.S. person or eligible to access without required export authorization or be reasonably likely to obtain it.