Member of Technical Staff, Agent Harness

Threeum

Threeum is a frontier company building physical AI. We design the model and the machine as one system, so the full loop of training, deployment, and improvement runs faster, more capable, and more autonomous. Our goal is to make frontier AI physical, and to make it widely accessible.

The Role

We are looking for an engineer to build the harness our models act through: the tools, memory, permissions, and guardrails between a model and a machine.

Some example areas you might work on (not limited to):

• Design the action interface between models and physical systems, with permissions that mean something
• Build long-horizon memory and context management for agents that run for weeks
• Make agent behavior observable, replayable, and debuggable

If you want to build the machines the models deserve, we would love to hear from you.

We offer a base salary of $250,000 to $400,000 USD and a meaningful equity grant, depending on experience and background, along with competitive benefits.