AI Engineer, RL & Evals

About the company Our client is a seed-stage AI company building the data and infrastructure layer that improves model quality in subjective, creative domains, starting with design. It has raised $18.5M and has revenue-generating partnerships with frontier AI labs and application-layer companies. Its products support post-training, reinforcement learning, context and verification. The role As AI Engineer, RL & Evals, you will build reinforcement learning environments, evaluation frameworks and production infrastructure for creative domains. You will combine backend or full-stack product engineering with applied ML and own systems from design through delivery. What you'll do • Build and scale RL environments and evaluation frameworks for creative, non-verifiable domains. • Design tasks and grading rubrics that capture design quality and taste. • Build agent harnesses, context layers and supporting product infrastructure. • Collaborate with internal research teams and frontier labs to improve model output quality. • Ship production code end to end and build reliable backend systems and data pipelines. Requirements What we're looking for • 2-7 years of relevant AI or reinforcement learning engineering experience, with depth building RL environments, evaluation systems or ML post-training systems. • Strong full-stack or backend engineering skills and demonstrated production shipping experience. • Experience with Python, PyTorch, RL, ML evaluation frameworks and LLMs. • Knowledge of distributed systems and data pipelines; relevant scraping, indexing, embedding or agent-harness work is valuable. • A computer science degree and fluent English communication. • Ability to work in the San Francisco office five days per week. Bonus points • Experience at creative technology, generative AI, crawling, indexing or data companies. • Building agentic frameworks or evaluations for non-verifiable domains. • Experience connecting research work to practical products and infrastructure. Benefits Compensation and benefits • $175,000-$275,000 annual base salary. • Competitive equity. Location and work model Full-time, on-site five days per week in Levi's Plaza, San Francisco, California. Visa transfers, including OPT and H1B transfers, are supported.