Lead AI/ML Data Scientist

Nightfall is seeking a Lead Applied Scientist to join the AI Engineering organization. You will create ML/NLP models and Gen AI solutions for data leak protection, leading research and guiding engineers to production. This hybrid role is based in Palo Alto, California.

• Fast-paced, hands-on execution; creatively apply statistical and ML modeling for enterprise security; create, train, and fine-tune NLP, LLMs, and other models; take prototypes to production through the full ML lifecycle; shape AI platform architecture for scale and cost efficiency; champion data-driven engineering.

• 5+ years of technical development experience; 5-10 years mentoring and leading Data Science or ML Engineering teams; strong Python and at least one other language (Go, C++, Java, Rust); knowledge of data structures and algorithms; proficiency in training custom transformers, LLMs, and deep learning; BS/MS/PhD in Computer Science, Applied Math, or related field.

• Experience in high-growth venture-backed startups; prior AI in security (PII, health data); ML training/inferencing at scale with GPUs; conversational/agentic systems; familiarity with ML frameworks (SageMaker, MLflow, Vertex AI); AWS experience; teaching or mentoring outside of work.