# Member of Technical Staff - Pre-Training Data at Reflection AI - Company: Reflection AI - Status: Open - Workplace: On-site - Location: San Francisco, CA - Level: Staff - Discipline: AI & ML - Employment: Full-time - Posted: 2026-10-22 - Skills: Python, Kubernetes, PyTorch - Apply: https://jobs.ashbyhq.com/reflectionai/2b0b0fbf-0e82-4212-be2e-36e4ca37756c ## Description OUR MISSION Reflection is a research lab making intelligence open and accessible for everyone to use, customize, and build on. We build open models that let anyone control their intelligence and help shape the future of AI. Our mission: make intelligence open and accessible to all. What You’ll Do: - Design and implement techniques for sourcing, curating, and filtering large-scale web, text, and code data, with opportunities to extend into other modalities as our models evolve. - Develop data quality metrics and analyses that measure coverage, diversity, and representativeness across sources. - Join the pre-training research team to design and run data experiments, working with infrastructure teams to scale the supporting data systems efficiently and reproducibly - Investigate and mitigate data risks, including privacy, safety, and licensing concerns, to support responsible and ethical data use. - Evaluate dataset changes through ablations and scaling experiments, tracing their downstream effects on model learning and behavior. - Publish and present research, and share code, datasets, and insights that move the open AI community forward. What We're Looking For: - Proficiency in Python and familiarity with at least one deep learning framework (e.g., PyTorch or JAX), with experience debugging distributed workloads and writing code that scales. - Bachelor’s degree or equivalent experience in Computer Science, Machine Learning, Physics, Mathematics, or a related discipline with strong theoretical and empirical grounding. - Clear written communication and t More Reflection AI roles: https://deviantjobs.com/companies/reflection-ai