AI Researcher - Post-Training

Senior On-site Geneva, Switzerland Full-time Posted 2 months ago

Skills & stack

Languages

Python

Skills

Fine-tuning LLM Reinforcement Learning

About the role

SonarSource is hiring a Senior AI Researcher for Post-Training, based in its Geneva, Switzerland office. You will combine static analysis with large language model post-training to develop enterprise coding agents that meet software development standards.

Work format

This is a full-time position with C1 English specified. Office anchor days are Monday, Tuesday and Thursday.

Skills and tools

Python
Reinforcement Learning
LLM
Fine-tuning
GRPO
PPO
RLVR
SFT
PEFT
Rust
C#
C++
JS/TS
Java

What to prepare

Prepare a Python work sample showing an LLM post-training method and how you evaluated its results.
Outline a research-to-product example, covering your hypothesis, experiments, prototype and contribution.

Responsibilities

Develop products that let customers post-train models for agentic coding.
Design hypotheses and experiments with researchers, research engineers, MLOps and engineers, turning proofs of concept into products.
Contribute technical ideas to discussions on enterprise coding model post-training.
Track LLM and agentic research developments and share findings with technical and non-technical audiences.

Requirements

4+ years of machine learning industry experience and an understanding of software engineering practices and tools.
Python fluency, including core machine learning frameworks.
LLM post-training expertise, including reinforcement learning, policy optimization with GRPO or PPO, and verifier-based RL.
Experience with supervised and parameter-efficient fine-tuning, synthetic data, data curation, and preference and safety alignment.
A record of driving research projects, producing findings and prototypes, and converting them into products.
English communication skills that support clear explanations of complex scientific topics.

Nice to have

Experience with Rust or SonarQube languages such as C#, C++, JS/TS or Java.

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SonarSource

Product

Geneva-headquartered maker of SonarQube, SonarQube Cloud and SonarQube for IDE, the code quality and code security platform used by developers and enterprises worldwide. 800+ employees across 11 offic

Location: Geneva, Switzerland
Team size: 501-1000
Remote policy: Hybrid

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