Member of Technical Staff - Post-Training

Reflection AI
San Francisco, New York, London
Workplace: OnsiteFull timeFunction: Education & TrainingSkills: ["Communication","Collaboration","Problem-solving","Bias toward action","Strategic thinking"]

Role focused on transforming pre-trained models into aligned, general agents through post-training research and engineering. You will drive large-scale ML initiatives, develop data generation and RL techniques, and collaborate across pre-training/post-training teams to push model capabilities while advancing understanding of how large models learn and improve.

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FursaFursa
Reflection AI
Reflection AI
11 months ago

Member of Technical Staff - Post-Training

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Canonical indexed version, validated from employer's careers page.

Source: Company careers pageValidated by: Fursa AI
Last checked: 2 hours agoStatus: Live

Job Summary

Role focused on transforming pre-trained models into aligned, general agents through post-training research and engineering. You will drive large-scale ML initiatives, develop data generation and RL techniques, and collaborate across pre-training/post-training teams to push model capabilities while advancing understanding of how large models learn and improve.
Location: San Francisco, New York, London
Workplace: Onsite
Employment Type: Full time
Job Function: Education & Training

Key Responsibilities

  • •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.

Pay and Benefits

Perks:Health InsuranceDentalVisionLifeDisability InsuranceParental LeaveRelocationEquity

Key Requirements

  • •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 through data, reward modeling, or RL techniques.
  • •Evidence of owning ambitious research or engineering agendas that led to measurable model improvements.
  • •Thrive in a fast-paced, high-agency startup environment; bias toward action and clarity of execution.
Experience:AIMLLLM
Skills:CommunicationCollaborationProblem-solvingBias toward actionStrategic thinking
Languages:English
Tech Stack:PythonDistributed systemsReinforcement learningReward modelingData generationLLMsLarge language models

Company Brief

Reflection AI
Builds frontier autonomous AI systems focused on autonomous coding agents (product: Asimov) to create organizational superintelligence, founded by former DeepMind/Google researchers and hiring across SF, NYC, London.
Industry: AI & Machine Learning
Company Size: Small (11 to 50 employees)
Growth: Growth Stage Startup
Funding: Series A
Headquarters: San Francisco, United States
Founded: 2024
WebsiteLinkedInGlassdoor