Reflection

Member of Technical Staff - Post-Training

Reflection
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12 months ago
London, United Kingdom +2 moreSenior
H1B sponsor

Responsibilities

  • Build systems that transform pretrained models into aligned and general agents.
  • Drive research and engineering initiatives in post-training, including data curation and large-scale optimization.
  • Develop data-generation pipelines, reward models, reinforcement-learning algorithms, and inference-time scaling techniques.
  • Collaborate with pre-training and post-training teams to deliver substantial gains in model capability.
  • Advance understanding of how large models learn to reason, follow instructions, and improve through reinforcement learning.

Requirements

  • Deep understanding of machine-learning fundamentals and practical experience with large-scale LLM training.
  • Strong engineering skills and comfort working in complex machine-learning codebases and distributed systems.
  • Experience improving model behavior through data, reward modeling, or reinforcement-learning techniques.
  • Evidence of owning ambitious research or engineering agendas that produced measurable model improvements.
  • Ability to work across research and infrastructure boundaries in a fast-paced startup environment.
  • Strong communication and collaboration skills, with a passion for advancing the frontier of intelligence.

Benefits

  • Top-tier compensation and equity, with no specific base salary stated.
  • Comprehensive medical, dental, vision, life, and disability insurance.
  • Fully paid parental leave for all new parents, including adoptive and surrogate journeys, plus family-planning financial support.
  • Paid time off and relocation support.
  • Daily lunch and dinner, regular off-sites, and team celebrations.

Categories

AI ResearchML Engineering
Reflection

About Reflection

201-500 employees

Reflection is a New York–based, privately held research lab developing open foundational AI models and agentic coding tools for developers, enterprises, and public-sector users. The team includes former researchers from DeepMind, OpenAI, and Anthropic, and their work focuses on transparent, customizable systems that organizations can deploy with ownership and control.

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