Character.AI
AI

Research Engineer, ML Systems (All Industry Levels)

Character.AI · Redwood City, CA · $225k - $400k

Actively hiring Posted 19 days ago

Responsibilities

  • Write efficient Triton kernels and tune them for our specific models and hardware
  • Develop prefix-aware routing algorithms to improve serving cache hit rate
  • Train and distill LLMs to improve latency while preserving accuracy and engagements
  • Build an efficient and scalable distributed RLHF stack powering the model innovations
  • Develop systems for efficient multimodal (image gen/video gen) model training & inference
  • "All Industry Levels": at least PhD (or equivalent) research experience
  • Write clear and clean production system code
  • Strong understanding of modern machine learning techniques (reinforcement learning, transformers, etc)
  • Track record of exceptional research or creative ML systems projects
  • Comfortable writing model development code (PyTorch) for either training or inference

Preferred qualifications

  • Experience training large models in a distributed setting utilizing PyTorch distributed, DeepSpeed, Megatron.
  • Experience working with GPUs & collectives (training, serving, debugging) and writing kernels (Triton, CUDA, CUTLASS).
  • Experience with LLM inference systems and literature such as vLLM and FlashAttention.
  • Familiarity with ML deployment and orchestration (Kubernetes, Docker, cloud)
  • Publications in relevant academic journals or conferences in the field of machine learning and systems

About the company

Joining us as a Research Engineer on the ML Systems team, you’ll be working on cutting-edge ML training and inference systems, optimizing the performance and efficiency of our GPU clusters, and developing new technologies that fine-tune leading consumer AI models with a data flywheel, and serve 20K+ QPS in production with LLMs. Your work will directly contribute to our groundbreaking advancements in AI, helping shape an era where technology is not just a tool, but a companion in our daily lives. At Character.AI, your talent, creativity, and expertise will not just be valued—they will be the catalyst for change in an AI-driven future.

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Fulltime Remote Ai Machine Learning

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