Member of Technical Staff - Post-Training

Job description

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: Build systems that transform powerful pre-trained models into aligned and general agents. Drive research and engineering initiatives that push the frontier of post-training, from data curation to large-scale optimization. Develop data generation pipelines, reward models, reinforcement learning algorithms, and inference-time scaling techniques. Collaborate across pre-training and post-training teams to deliver step-function gains in model capability. Contribute to shaping our understanding of how large models learn to reason, follow instructions, and improve through reinforcement learning. About You: Deep understanding of machine learning fundamentals and practical experience with large-scale LLM training. Strong engineering skills, comfortable diving into complex ML codebases and distributed systems. Experience improving model behavior throug...