Applied AI Engineer, Video Agent

HeyGen is hiring an Applied AI Engineer for the Video Agent team to help build, evaluate, and ship an AI agent that converts prompts and assets into finished videos.

Responsibilities

• Build the agent: design the tools, prompts, and context the agent uses
• Improve planning quality and recovery from mistakes
• Enhance support for long, multi-turn conversations
• Measure quality by building evals and creating offline replays of real sessions
• Run experiments using feature flags, review results honestly, and interpret what improved performance
• Monitor real user sessions and agent traces to diagnose where failures occur
• Ship across the stack by building user-facing features with TypeScript and React
• Develop backend services and long-running workflows in Python and Go
• Collaborate with product managers, design, research, and rendering teams the agent depends on

Requirements

• Experience building and shipping an AI agent used by real people, where a model calls tools, plans across multiple steps, and acts on results
• Ability to evaluate improvement: built evals or test sets for model behavior and can distinguish real gains from noise
• 2+ years of professional experience as a full-stack engineer
• Fluency with TypeScript and React (frontend)
• Fluency with Python (backend)
• Strong product sense: uses what you build, cares about user experience, and analyzes real customer usage
• Ownership mindset: doesn’t wait for a spec, identifies the most important problem, fixes it, and communicates what changed

Technologies

• TypeScript
• React
• Python
• Go
• A/B tests
• Feature flags

Benefits

• $180,000 – $240,000 annually
• Equity in a high-growth AI company
• 401K match
• Health, dental, and vision benefits
• Flexible PTO
• Opportunity to help define a new category in AI video
• High ownership, high velocity, and direct impact on revenue growth

Nice to Have

• Fine-tuned models experience
• Experience working on code-to-video models (video generation by writing code such as HTML or animation scripts)
• Experience working on video agent models

Application: Show Us an Agent You’ve Built

• Include a short note (a few sentences) describing an agent you built: what it does, how you measured whether it worked, and one failure you found and fixed
• Code, demo, or write-up is a bonus

Location: San Francisco, CA (onsite)

Minimum experience: 2 years