Member of Technical Staff - Pre-Training

Our Mission Reflection’s mission is to build open superintelligence and make it accessible to all . We’re developing open weight models for individuals, agents, enterprises, and even nation states. Our team of AI researchers and company builders come from DeepMind, OpenAI, Google Brain, Meta, Character.AI, Anthropic and beyond. About the Role Research and build solutions across algorithms, scaling laws, data processing, optimizers, and model architecture. Design and run scientific experiments to advance our understanding of scaling large language models and data efficiency. Implement state-of-the-art methods from the deep learning literature. Lead small research projects independently while collaborating on larger initiatives Optimize the training infrastructure for efficient scaling. Contribute across the entire stack, from low-level optimizations to high-level model design. About You Graduate degree (MS or PhD) in Computer Science, Machine Learning, or related discipline. Solid software engineering capabilities with experience building large-scale systems. Experience with large-scale ETL workflows and training data preparation. Deep understanding of large-scale ML, especially as it relates to language models, distributed training, and scaling. Proficient in Python and deep learning frameworks (PyTorch preferred). Navigate trade-offs between research objectives and practical engineering realities. Thrive in a fast-paced, high-agency startup environment with bias toward action. Strong communication capabilities and comfort working collaboratively. Passionate about advancing the frontier of intelligence. What We Offer: We believe that to build superintelligence that is truly open, you need to start at the foundation. Joining Reflection means building from the ground up as part of a small talent-dense team. You will help define our future as a company, and help define the frontier of open foundational models. We want you to do the most impactful work of your career with the confidence that you and the people you care about most are supported. Top-tier compensation: Salary and equity structured to recognize and retain the best talent globally. Health & wellness: Comprehensive medical, dental, vision, life, and disability insurance. Life & family: Fully paid parental leave for all new parents, including adoptive and surrogate journeys. Financial support for family planning. Benefits & balance: paid time off when you need it, relocation support, and more perks that optimize your time. Opportunities to connect with teammates: lunch and dinner are provided daily. We have regular off-sites and team celebrations.