Character.AI · 2 weeks ago
Research Engineer, ML Systems (All Industry Levels)
San Francisco Bay Area
Full-time
Onsite
Entry, Mid, Senior LevelCharacter.AI empowers people to connect, learn and tell stories through interactive entertainment. As a Research Engineer on the ML Systems team, you will work on optimizing ML training and inference systems, improving GPU cluster performance, and developing technologies that enhance consumer AI models.
AppsArtificial Intelligence (AI)Foundational AIGenerative AIInformation TechnologyMobile AppsSoftware
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
Qualification
Required
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
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
Company
Character.AI
Character.ai provides open-ended conversational applications in which users create characters and converse with them.
Founded in 2021
51-200 employees
H1B Sponsorship
Character.AI has a track record of offering H1B sponsorships. Please note that this does not
guarantee sponsorship for this specific role. Below presents additional info for your
reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2025 (9)
2024 (16)
2023 (6)
2022 (1)
Funding
Current Stage
Growth StageTotal Funding
$150.08MKey Investors
Andreessen Horowitz
2023-03-23Series A· $150M
2023-01-24Seed· $0.08M
Leadership Team
Karandeep Anand
CEO
Recent News
Irish Tech News
2026-01-16
Company data provided by crunchbase