Character.AI
AI

Research Engineer, ML Systems (All Industry Levels)

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

Actively hiring Posted about 6 hours 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.

Tags & focus areas

Used for matching and alerts on DevFound
Fulltime Remote Ai Machine Learning

Next step

Ready to Join the Team?

Apply once with DevFound. We'll route your profile to Character.AI and keep you informed when matching AI roles go live.

  • Single profile, multiple curated AI opportunities
  • No spam roles — only vetted AI positions
  • You choose which roles to apply to
Sign up to apply

No CV uploads. We never share your profile without your consent.