Member of Technical Staff - Pretraining

ABOUT BLACK FOREST LABS

We’re the team building the foundational layer for visual intelligence: multimodal models trained jointly on images, video, audio, and action to see, generate, and understand the world.

Our founding team pioneered latent diffusion and Stable Diffusion, the breakthroughs that made generative AI accessible to millions. With FLUX, we're pushing into generative media at scale, machines that act in the physical world, and emerging applications in computer use.

Our FLUX models top public benchmarks and run in production in some of the world's biggest platforms. We're a small, fast growing research lab competing with the largest companies in the world. From our labs in Freiburg to San Francisco, we're building what comes next.

WHY THIS ROLE

We're building the foundation models that power the next wave of visual intelligence — and pretraining is where that work begins. This role sits at the center of our research effort. You'll shape training objectives, architectures, data strategies, and systems behind our joint image, video, and audio foundation models, with a direct line from your research to products used by millions.

This is a Staff / Senior IC role. We're looking for someone who has already led pretraining at the frontier and wants to do it again.

WHAT YOU'LL WORK ON

• Lead large-scale pretraining experiments for our multimodal (image, video, audio) foundation models (architecture, objective functions, scaling strategies)
• Develop and evaluate novel ideas across architecture, optimizers, and training algorithms.
• Contribute across the full stack: low-level GPU and systems optimizations, research code, and high-level model design
• Lead focused research projects independently and drive larger cross-team initiatives

WHAT WE'RE LOOKING FOR

• You've led or co-owned pretraining for a foundation model (image, video, LLM, or multimodal) that shipped to production or a major release
• Own architectural calls that move the model: attention patterns, modulation schemes, loss formulations, tokenization strategies
• Deep experience with large-scale distributed training: FSDP/TP/PP, multi-node runs at 500+ GPUs, debugging loss spikes, NaNs, throughput regressions, and silent correctness issues at scale
• Strong intuition for architecture and objective design — you've made calls on attention patterns, modulation schemes, or loss formulations that moved a real model
• Track record of shipping: top-venue publications (NeurIPS, ICML, ICLR, CVPR, ICCV, ECCV) paired with production impact, or unambiguous production wins at a frontier lab
• Deep Python and PyTorch proficiency; comfortable reading and modifying low-level training code
• Familiarity with visual generative models is a must

HOW WE WORK TOGETHER

We’re a distributed team with real offices that people actually use. This role is based in Freiburg, and you’ll join us in the office at least 2 days a week, or one full week every other week.

EVERYTHING WE DO IS GROUNDED IN FOUR VALUES:

• Obsessed. We are a frontier research lab. The science has to be right, the understanding deep, the product beautiful.
• Low Ego. The work speaks. The best idea wins, no matter who said it. Credit is shared. Nobody is above any task.
• Bold. We take the ambitious bet. We ship, we do not wait for conditions to be perfect.
• Kind. People over politics. We treat each other with genuine warmth. Agency without empathy creates chaos.

If this sounds like work you’d enjoy, we’d love to hear from you.

Base Annual Salary:

EU €130,000-€340,000 + Equity

Note: We may use AI-assisted tools to help organize applications. All hiring decisions are always made by our team.