ReflectionAI

ReflectionAI

Member of Technical Staff - Mid-Training Infra

San Francisco · Staff+

H1B sponsorship availableDetected 119 days ago
Distributed SystemsData EngineeringNLPLLMsResearch

About the role

  • Improve performance of model execution through kernel-level optimization, model parallelism strategies, and GPU runtime improvements.
  • Diagnose and resolve performance bottlenecks across inference runtimes, GPU kernels, networking, and distributed compute systems.

Responsibilities

  • Reflection is a research lab making intelligence open and accessible for everyone to use, customize, and build on.
  • We build open models that let anyone control their intelligence and help shape the future of AI.
  • Design, build, and operate large-scale GPU infrastructure for high-throughput model inference and mid-training workloads.
  • Build high-performance inference platforms capable of serving and evaluating models across thousands of GPUs.
  • Work closely with research teams to support distributed RL workloads and large-scale model evaluation infrastructure.
  • Develop distributed systems that enable large-scale synthetic data generation and RL-driven training workflows.
  • Sponsorship support: We sponsor visas to help exceptional talent join our team and support long-term immigration pathways where applicable.
  • Team building: We have regular off-sites, happy hours, and team celebrations.
  • Joining Reflection means building from the ground up as part of a talent-dense team.

Requirements

  • Experience deploying and operating large-scale GPU systems for inference or model serving.
  • Strong understanding of GPU performance characteristics and optimization techniques.
  • Experience optimizing throughput for large-scale model execution workloads.
  • Experience working with GPU kernels or low-level performance optimization.
  • Familiarity with infrastructure used for synthetic data pipelines or RL training workflows.
  • Experience debugging performance issues across GPU, networking, and distributed execution layers.

Skills

  • Experience working with modern inference frameworks such as SGLang, Megatron, or similar high-performance LLM runtimes.

Compensation

  • Salary and equity structured to recognize and retain our talent globally.
  • Health & wellness: Comprehensive medical, dental, vision, and life, with an annual wellness allowance.

Benefits

  • Top-tier compensation: Salary and equity structured to recognize and retain our talent globally.
  • Stock options: Everyone who joins and contributes to Reflection's success gets to share in the upside through stock options.
  • Health & wellness: Comprehensive medical, dental, vision, and life, with an annual wellness allowance.
  • Life & family: 22 weeks paid parental leave for all new birthing and non-birthing parents, including adoptive and surrogate journeys.
  • Vacation days: Unlimited paid time off in the U.S. and 30 days in the U.K.

Company info

  • make intelligence open and accessible to all.

Visa & Work Authorization

  • We sponsor visas to help exceptional talent join our team and support long-term immigration pathways where applicable.

This listing is sourced directly from ReflectionAI's careers page and normalized into a canonical job model.