Senior ML Researcher — Diffusion & RL for Creative AI

AI Chopping Block; San Francisco, Northern (CA, KY); Hybrid; USD 190,000 - 230,000; Full time

Benefits offered by this job

Competitive salary

Equity package

Health & dental insurance

Flexible PTO

401k match

Meals in office

Transit covered

Visa sponsorship

Job summary

Krea seeks a senior research engineer to advance AI creative tooling in its San Francisco in-person office. You will lead diffusion model fine-tuning, implement posttraining strategies, and design robust evaluation and reward systems.

The role emphasizes scalability, safety alignment, and collaboration with research and engineering teams to push state-of-the-art methods and product-ready innovations.

Qualifications

• Proven work with posttraining diffusion models for image/video generation.
• Experience with large-scale model training, inference, and optimization.
• Strong understanding of LLM and diffusion post-training pipelines and algorithms.

Responsibilities

• Finetune diffusion models at scale to improve image aesthetics.
• Implement posttraining techniques including supervised finetuning, preference optimization, RL, and distillation methods.
• Design eval suites and reward designs for RL focused on image space.

Skills

Posttraining diffusion

Large-scale model training

PyTorch

Reinforcement learning

Evaluation design

Tools

vLLM

sglang

slime

miles

tinker

verl

Job description

Krea seeks a senior research engineer to advance AI creative tooling in its San Francisco in-person office. You will lead diffusion model fine-tuning, implement posttraining strategies, and design robust evaluation and reward systems.

The role emphasizes scalability, safety alignment, and collaboration with research and engineering teams to push state-of-the-art methods and product-ready innovations.