Senior/Staff Applied AI Engineer, Agent Harness

David Joseph & Company is hiring an Applied AI Engineer at the Senior/Staff level to help build production-grade agent systems for real customer workflows. You’ll work onsite in San Francisco, CA (Monday to Friday) with startup intensity, and you’ll get meals in the office, health insurance, and unlimited PTO.

This role centers on taking model capability and turning it into deterministic, reliable execution that can ship. You’ll own the core agent harness and the execution layer, run evals against replicas of customer environments, and drive systematic robustness improvements backed by production failure analysis.

What you’ll own

• Core agent harness: execution loop, tool-use strategies, context construction, and model-facing experimentation
• Agent behaviors across real customer workflows and long-horizon tasks
• Deterministic execution boundary between runtime model decisions and deterministic, compiled, type-checked execution
• Evals for release gating using replicas of real customer environments that are reliable enough to determine readiness
• Production failure analysis and systematic robustness improvements attributed by layer
• Extending computer-use to API-less environments with production guarantees: per-task microVM, model-blind credentials, full action recording, and killable sessions
• Feedback loops and data systems to improve real-task data that feeds evals and training

What you bring

• 4+ years of engineering experience
• Experience with agent frameworks or tool-using LLM systems
• Strong in Python or TypeScript, comfortable with modern AI tooling
• Experience with model evaluation, fine-tuning, or prompt design
• Ability to own systems end-to-end and debug across the stack
• Systems thinking focused on user outcomes, not only model metrics
• Enjoys debugging messy, real-world failures and converting them into durable improvements
• Interest in the layer that turns model capability into systems that work for users
• Can work in person in San Francisco, Monday to Friday, at startup intensity

Helpful experience

• Built computer-use or browser-automation agents
• Experience with virtualization and sandboxed execution environments, including scaling
• AI research and publications at top conferences
• Shipped systems where correctness survives partial failure (idempotency, resumability, compensating actions)
• Integrated enterprise SaaS APIs (identity providers, directory services, ticketing, ERPs)
• Experience with large, messy datasets or production logs
• Early engineering experience that required talking to customers

Role details

• Location: San Francisco, CA (onsite)
• Employment: Full-time
• Level: Senior / Staff
• Experience: 4+ years
• Salary: USD 200,000 - 300,000 per year
• Visa sponsorship: Available (H-1B, O-1, OPT)

Interview process

• Culture screen
• Second culture screen
• Technical interview
• One-day onsite
• Offer