Founding Machine Learning Engineer
About the Role
This is a founding ML engineering role at an early-stage AI startup, sitting at the intersection of post-training, agent systems, and research infrastructure. You will own the ML function from day one, working closely with the founding team to define technical direction, run experiments, and build the systems that power the next generation of AI agents.
What You'll Do
Structure, filter, and score experimental trajectories to build high-quality training data pipelines.
Design and implement evaluation frameworks and benchmarks that measure model reasoning, planning, and improvement.
Build reliable agent environments, tool interfaces, observability systems, and replay infrastructure.
Establish robust validation and provenance tracking for trajectory and data quality.
Set ML roadmap priorities across systems, experiments, and hiring decisions.
Lead and grow the ML team as the company scales.
What We're Looking For
3 or more years of machine learning engineering experience delivering production ML systems.
Hands-on experience with post-training
