Member of Engineering (Post-training)

Poolside
Europe / North America / Paris, France2026-04-21Remote

About the job

You would be working as part of our Applied Research team, focused on turning pre-trained LLMs into well-aligned and highly capable AI systems for coding and software development. This is a hands-on role where you'll work across a variety of efforts, including: Building data pipelines and environments for agentic use cases, researching and implementing post-training algorithms, designing experiments and testing hypothesis, and more. You will have access to thousands of GPUs in this team.

Responsibilities

- Research and experiment on ways to specialize foundational models to agentic use cases

- Build and maintain data and training pipelines

- Keep up with latest research, and be familiar with state of the art in LLMs, alignment, synthetic data generation, code generation

- Design, analyze, and iterate on training/fine-tuning/data generation experiments

- Write high-quality, pragmatic code

- Work as part of a team: plan future steps, discuss, and communicate clearly with your peers

Qualifications

Minimum

- Experience with Large Language Models (LLM)

- Deep knowledge of Transformers

- Strong deep learning fundamentals

- Good taste in data

- Post-training experience with LLMs

- Extensively used and probed LLMs, familiarity of their capabilities and limitations

- Knowledge of distributed training

- Strong machine learning and engineering background

- Research experience

- Experience in proposing and evaluating novel research ideas

- Familiar with, or contributed to the state of the art in multiple of the following topics: Fine-tuning and alignment of LLMs, synthetic data generation, continual learning, RLVR, code generation

- Is comfortable in a rapidly iterating environment

- Is reasonably opinionated

- Programming experience

- Linux

- Strong algorithmic skills

- Python with PyTorch or Jax

- Use modern tools, including latest code agents and are always looking to improve

- Strong critical thinking and ability to question code quality policies when applicable

Preferred

- Prior experience in non-ML programming, especially not in Python - is a nice to have