Senior AI Engineer, Post-Training
Core
Lead end-to-end post-training of open-weight LLMs on proprietary legal data for Carta's autonomous AI agents and legal tech platform.
Role type
Senior IC machine-learning engineer (post-training)
Builds
Production-ready legal AI models, training pipelines, and agent systems for private capital workflows
Domain
Legal technology + Large Language Models
Deliverable
production ML models
Required skills
LLM post-training, supervised fine-tuning, preference optimization, reinforcement learning, distributed training, model serving, data pipeline construction, reward/grader design
Preferred skills
Experience with PyTorch, building production AI systems, translating domain workflows into model decisions
Technologies
PyTorch, open-weight language models
Responsibilities
Post-train models on proprietary legal data; design training objectives and evaluation metrics; build and optimize training datasets and pipelines; operate model serving and evaluation infrastructure; partner with product engineers on model/system co-design; collaborate with lawyers to translate workflows into technical decisions
Seniority
Senior, hands-on IC