Applied Machine Learning Engineer

Help us build the systems that train specialized AI models for the fastest-growing companies in the world. If you love taking cutting-edge ML techniques and turning them into products that ship, we'd love to meet you.

trains and hosts specialized language models for companies who want frontier-quality AI at a fraction of the cost. The models we train match GPT-5 accuracy but are smaller, faster, and up to 90% cheaper. Our platform handles everything end-to-end: distillation, training, evaluation, and planet-scale hosting.

We are a well-funded ten-person team of engineers who work in-person in downtown San Francisco on difficult, high-impact engineering problems. Everyone on the team has been writing code for over 10 years, and has founded and run their own software companies. We are high-agency, adaptable, and collaborative. We value creativity alongside technical prowess and humility. We work hard, and deeply enjoy the work that we do.

Most of us are in the office 4 days a week in SF; hybrid works for Bay Area candidates.

You will be responsible for building and improving the core ML systems that power our custom model training platform, while also applying these systems directly for customers. Your role sits at the intersection of applied research and production engineering. You'll lead projects from data intake to trained model, building the infrastructure and tooling along the way.

Your north star is model quality at scale, measured by how well our custom models match frontier performance, how efficiently we can train and serve them, and how smoothly we can deliver results to our customers. You'll own the full training lifecycle: processing data, creating dashboards for visibility, training models using our frameworks, running evaluations, and shipping results. This role reports directly to the founding team.

You'll have the autonomy, a large compute budget / GPU reservation, and technical support to push the boundaries of what's possible in custom model training.

• Lead projects from data intake through the full training pipeline, including processing, cleaning, and preparing datasets for model training

• Build and maintain data processing pipelines for aggregating, transforming, and validating training data

• Create dashboards and visualization tools to display training metrics, data quality, and model performance

• Train models using our internal frameworks and iterate based on evaluation results

• Develop robust benchmarks and evaluation frameworks that ensure custom models match or exceed frontier performance

• Build systems to automate portions of the training workflow, reducing manual intervention and improving consistency

• Take research features and ship them into production settings

• Apply the latest techniques in SFT, RL, and model optimization to improve training quality and efficiency

• Collaborate with infrastructure engineers to scale training across our GPU fleet

• Deeply understand customer use cases to inform training strategies and surface edge cases

• 2+ years of experience training AI models using Py Torch

• Hands‑on experience with post‑training LLMs using SFT or RL

• Strong understanding of transformer architectures and how they're trained

• Experience with LLM‑specific training frameworks (e.g., Hugging Face Transformers, Deep Speed, Axolotl, or similar)

• Experience training on NVIDIA GPUs

• Strong data processing skills and comfortable building ETL pipelines and working with large datasets

• Track record of creating benchmarks and evaluations

• Ability to take research techniques and apply them to production systems

• Experience with model distillation or knowledge transfer

• Experience building dashboards and data visualization tools

• Familiarity with vision encoders and multimodal models

• Experience with distributed training at scale

• Contributions to open‑source ML projects

You don't need to tick every box. Curiosity and the ability to learn quickly matter more.

We offer competitive compensation, equity in a high-growth startup, and comprehensive benefits. The base salary range for this role is $220,000 - $320,000, plus equity and benefits, depending on experience.

is an equal opportunity employer. We welcome applicants from all backgrounds and don't discriminate based on race, color, religion, gender, sexual orientation, national origin, genetics, disability, age, or veteran status.

If you're excited about building the future of custom AI infrastructure, we'd love to hear from you. Please send your resume and Git Hub to and/or apply here on Ashby.