Member of Technical Staff Post Training

Reflection is an AI research lab building open frontier models and a full AI stack for developers, enterprises, and public-sector users.

New York, United States
About Reflection

Reflection develops open-weight AI models, open-source software for customizing and running agents, AI-factory infrastructure, and related solutions. Its current research emphasizes large language models, reinforcement learning, and agentic reasoning.

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Skills

About the Role

You will build systems that transform pre-trained models into aligned and general agents. You will develop data-generation pipelines, reward models, reinforcement-learning algorithms, and inference-time scaling techniques, while collaborating across pre-training and post-training work to improve model capabilities.

Requirements

  • Machine learning fundamentals and practical experience with large-scale LLM training.
  • Engineering skills in complex machine-learning codebases and distributed systems.
  • Experience improving model behavior through data, reward modeling, or reinforcement-learning techniques.
  • Experience owning research or engineering agendas that produced measurable model improvements.
  • Ability to work across research and infrastructure boundaries.
  • Communication and collaborative working skills.

Responsibilities

  • Build systems that transform pre-trained models into aligned and general agents.
  • Drive post-training research and engineering initiatives.
  • Develop data-generation pipelines, reward models, reinforcement-learning algorithms, and inference-time scaling techniques.
  • Collaborate across pre-training and post-training work to improve model capability.
  • Advance understanding of model reasoning, instruction following, and reinforcement learning.

Benefits

  • Stock options.
  • Comprehensive medical, dental, vision, and life insurance.
  • Annual wellness allowance.
  • Daily in-office lunch and dinner.
  • 22 weeks of paid parental leave.
  • Unlimited paid time off in the U.S. and 30 days in the U.K.
  • Visa sponsorship and long-term immigration-pathway support where applicable.
  • Regular off-sites, happy hours, and team celebrations.
Member of Technical Staff Post Training at Reflection | JobStash