Member of Engineering (Post-training)

Poolside

United States

Remote

GBP 110,000 - 160,000

Full time

14 days+

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Benefits offered by this job

Fully remote work

37 days vacation & holidays

Health insurance allowance for you &/+

16 weeks of parental leave

Well-being & home office allowances

Company-provided equipment

Frequent team get togethers

Diverse & inclusive culture

Job summary

Poolside is seeking a highly skilled Applied Research team member to turn pre-trained LLMs into well-aligned, capable AI systems for coding and software development. You will work across data pipelines, post-training algorithms, and experimental design, with access to thousands of GPUs to accelerate research.

The role blends research and engineering, requiring deep learning expertise, Python, PyTorch or Jax, and a hands-on approach in a fast-moving environment with cross-functional collaboration.

Qualifications

Experience with Large Language Models (LLM) and Transformers.
Strong background in deep learning and model alignment research.
Proven ability to design and evaluate training/fine-tuning experiments.
Experience building data pipelines and experimentation environments.

Responsibilities

Research and experiment on specializing foundational models for agentic use cases.
Build and maintain data and training pipelines.
Stay current with state-of-the-art LLMs, alignment, and code generation research.
Design, analyze, and iterate on training/fine-tuning experiments.
Write clean, pragmatic code and collaborate with peers.

Skills

LLMs

Transformers

Deep learning

Data pipelines

Post-training

Distributed training

Research

Python

PyTorch

Jax

Tools

PyTorch

Jax

Docker

Job description

About Poolside

In this decade, the world will create Artificial General Intelligence. There will only be a small number of companies who will achieve this. Their ability to stack advantages and pull ahead will define the winners. These companies will move faster than anyone else. They will attract the world's most capable talent. They will be on the forefront of applied research, engineering, infrastructure and deployment at scale. They will continue to scale their training to larger & more capable models. They will be given the right to raise large amounts of capital along their journey to enable this. They will create powerful economic engines. They will obsess over the success of their users and customers.

Poolside exists to be this company: to build a world where AI will be the engine behind economically valuable work and scientific progress. We believe the fastest way to reach AGI lies in accelerating software development itself, by reshaping the developer experience with agentic systems, coding assistants, and the frontier models that power them. We deploy these systems directly into the development environments of security-conscious enterprises.

About Our Team

We were founded in the US and have our home there, but our team is distributed across Europe and North America. We get our fix of in-person collaboration (and croissants) in Paris each month for 3 days, always Monday-Wednesday, with an open invitation to stay the whole week. We also do longer off-sites once a year.

Our team is a multidisciplinary blend of research, engineering, and business experts. What unites us is our deep care for what we build together. We’re in a race that requires hard work, intellectual curiosity, and obsession; to balance this intensity, we’ve assembled a team of low ego and kind-hearted individuals who have built the special culture Poolside has. By building collaboratively and with intention, we create a compounding effect that moves the entire company forward towards our mission: reaching AGI through intelligence systems built for software development.

About The Role

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.

YOUR MISSION

To turn pre-trained LLMs into well-aligned and highly capable AI systems.

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

Skills & Experience

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

PROCESS