Research Engineer

The role

You will design and run training experiments to isolate the impact of datasets on model behavior. You will build post-training infrastructure for SFT and RL to measure how data affects capability, generalization, and alignment.

What you will do

• Design and build post-training infrastructure for SFT, RL and evaluation workflows.
• Build reliable pipelines for data preparation, dataset versioning, sampling, training, checkpoint management, and evaluation.
• Develop experiment orchestration and tracking systems.
• Create reusable abstractions to launch experiments across datasets, models, and training recipes.
• Integrate systems with partner-lab training stacks, model APIs, compute environments, and evaluation infrastructure.

Required qualifications

• At least 2 years of professional experience in machine learning engineering, research engineering, ML infrastructure, or a closely related field
• Strong Python and software-engineering skills.
• Hands on experience with PyTorch, JAX, Ray, and Slurm.
• Experience building production-quality ML training, evaluation, or data infrastructure.
• Hands-on experience with LLM fine-tuning, post-training, and evaluation.
• Ability to build reliable, reproducible systems for launching and comparing ML experiments.
• Strong debugging skills across distributed systems, data pipelines, training infrastructure, and model behavior.
• Understanding of experimental design and the ability to extract actionable conclusions from noisy results.
• Ability to move quickly between infrastructure engineering and hands-on experimentation.
• A bias toward building, testing, and shipping.

Nice to have

• 2-4+ years of professional experience in machine learning engineering, research engineering, ML infrastructure, or a closely related field

Benefits

• Medical, Vision, Dental
• 401(k) with Employer Match
• Daily UberEats Stipend
• Monthly Wellness Stipend

About the company

AfterQuery is an applied research lab curating data solutions for foundation model development. They serve frontier AI labs to deliver data to power models.