Full-Stack Engineer — AI Agent Infra & Observability

davidjoseph-co; San Francisco (CA); On-site; USD 200,000 - 300,000; Full time

Benefits offered by this job

Full benefits

Equinox membership

Private chef

Job summary

Judgment Labs is seeking a Full-Stack Engineer to own the product experiences and agent infrastructure from data layer to UI, in a San Francisco, CA on-site role. You will work 5 days per week in-person, collaborating with the founding team to deliver scalable agent monitoring infrastructure.

The role requires 3–7 years of full-stack engineering, hands-on LLM/agent-building, and strong customer-facing communication, with relocation supported.

Qualifications

• 3 to 7 years full-stack engineering experience.
• Hands-on LLM or agent-building experience.
• End-to-end production system ownership, data layer to UI.
• Customer-facing communication ability (approximately 30% of role).
• SF in-person 5 days per week, relocation supported.

Responsibilities

• Own the product experiences and agent infrastructure spanning data layer to UI.
• Shape large-scale parallel investigations across thousands of production traces.
• Build hosted simulated environments for stateful evals and trajectory replay.
• Design how engineers understand long traces, tool calls, decisions, and failures for quick insights.
• Develop and maintain the SDK and terminal-first experience for agent-dev sessions.

Skills

Full-stack development

LLM/agent-building

Production systems ownership

Customer-facing communication

Tools

SDK development

LLM infrastructure

Agent tooling

Job description

Judgment Labs is seeking a Full-Stack Engineer to own the product experiences and agent infrastructure from data layer to UI, in a San Francisco, CA on-site role. You will work 5 days per week in-person, collaborating with the founding team to deliver scalable agent monitoring infrastructure.

The role requires 3–7 years of full-stack engineering, hands-on LLM/agent-building, and strong customer-facing communication, with relocation supported.