Staff / Senior IC Post-Training Engineer (Fully Remote)

Overview

• We are the team behind Latent Diffusion, Stable Diffusion, and FLUX.
• Our models power tools used by millions of creators, developers, and businesses worldwide.
• We are headquartered in Freiburg, Germany with a growing presence in San Francisco.

What You'll Work On

• Own the full post-training pipeline end to end from data curation through deployment.
• Advance techniques across the stack: SFT, RLHF, RLAIF, DPO, preference learning, and reward modeling.
• Work across modalities: text-to-image, image editing, multi-reference, and video post-training.

What We're Looking For

• You have owned post-training for a frontier generative model through release.
• Deep experience across the post-training stack: reward modeling, preference learning, RLHF/RLAIF, and personalization.
• Strong PyTorch fluency and bias toward shipping measurable model-quality improvements.

How We Work Together

• We are a distributed team with offices in Freiburg and SF.
• You'll work in-person at least 2 days a week or remotely with a monthly in-person week.
• Our values are obsession, low ego, boldness, and kindness.

Black Forest Labs is a research lab behind foundational generative AI technologies like Stable Diffusion and FLUX, powering tools used by millions worldwide. They are a fast-growing, distributed team with a culture of research excellence, open science, and low ego.