Machine Learning Engineer

Location: Palo Alto, CA (Hybrid)

At Reinforce Labs, we partner directly with customers to build AI systems that enhance the safety and reliability of their complex, high-impact applications. In this role, you'll engage directly with clients to deeply understand their specific challenges, conduct thorough data analysis, and deliver trust and safety AI solutions. You'll implement advanced machine learning techniques including LLMs, reinforcement learning, and deep learning - often translating cutting-edge research papers into practical applications.

This position combines technical depth with significant client-facing responsibilities. You'll tackle high-stakes problems with unclear solutions but real-world consequences. Key responsibilities include:

• Conducting technical research with customers to map critical workflows and developing sophisticated AI probes that identify potential edge-case failures

• Performing comprehensive data analysis to build specialized classifiers that detect subtle risks, violations, and anomalies

• Implementing and fine-tuning generative models that can simulate rare or high-risk scenarios

• Designing systems that enhance human decision-making under pressure

Our success is measured by real-world impact. You'll develop and ship solutions that protect people and platforms at scale while building trusted relationships with the clients who depend on our technology.

• Experience with ML and deep learning frameworks such as PyTorch or TensorFlow

• Ability to translate cutting-edge research papers into practical AI applications

• Hands-on experience training and deploying machine learning models in production

• Proficiency in Python

• Experience partnering with trust & safety leads and background in trust & safety, moderation, AI safety, or security-focused ML to deliver state-of-the-art solutions [a big plus]

• An advanced degree in computer science or a related field

• LLM and agentic framework experience

• Experience in early-stage startups

• Experience in customer-facing AI technical solutions

• Contributions to high value AI/ML community projects

Reinforce Labs is a small team with a clear mission: to use AI to make critical systems safer, not just smarter.

We value:

• Willingness to learn new things, take on diverse tasks, and challenge yourself

• Hands-on technical excellence

• Ownership

• Ability to handle ambiguity

• Fast, results-driven delivery