Machine Learning Engineer — Applied AI & Agents

Build the learning systems behind security agents

At Cotool, we're building AI agents and the infrastructure around them to help security teams detect threats, investigate alerts, and respond. Our agents work across security tools and data, write and tune Python detections, and bring humans in when judgment or approval matters. Teams at Ramp, EliseAI, and ClickHouse use Cotool.

We're hiring a machine learning engineer to build the loop from agent behavior to training data, from training data to better models, and from better models to measurable improvements in production. You'll work across post-training, RL environments, evaluation, and deployment, with direct ownership of what reaches users.

• LLM fine-tuning pipelines. Curate and version datasets, turn useful trajectories and failure cases into training examples, run post-training experiments, and evaluate generalization on held-out tasks.