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# AI Researcher

- **Company:** Sonarsource
- **Location:** Bochum, Germany
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Clean Code Principles, Java (Programming Language), Artificial Intelligence, C Sharp (Programming Language), C++ (Programming Language), Static Program Analysis, Python (Programming Language), Machine Learning, Tensorflow, Software Engineering, SONAR (Symantec), SonarQube, Large Language Models, Information Technology, Optimization Algorithms, Machine Learning Operations
- **Published:** September 5, 2026
- **Apply:** https://startup.jobs/ai-researcher-post-training-f-m-d-sonarsource-8998552

## About the Role

* An advanced academic background (Master's or PhD) in Computer Science, Machine Learning, or a related quantitative field.
 * 4+ years industry experience in machine learning, with a solid understanding of modern software engineering practices and tools.
 * Fluency with Python including core ML frameworks, experience with Rust or any of SonarQube's flagship languages (C#, C++, JS/TS, Java) is a plus.
 * Expertise in post-training of large language models, including:
 * Policy optimization algorithms (e.g. GRPO, PPO)
 * Verifier-based RL frameworks (RLVR)
 * Supervised fine-tuning (SFT)
 * Data-centric AI methods, including synthetic data and curation
 * Parameter-efficient fine-tuning (PEFT)
 * Preference and Safety Alignment
 * Experience of driving research projects, delivering valuable findings and prototypes, and then converting them into products.
 * Excellent communication skills in English and a talent for explaining complex scientific topics clearly and concisely.

## Description

At Sonar, we are seeking an ambitious senior researcher to join our cross-disciplinary team, innovating and developing the next generation of solutions to build enterprise-grade coding agents and models. You will harness Sonar's deep experience in static analysis, and combine it with your experience and leading techniques in large language model post-training. If you are interested in being hands-on with state-of-the-art research, building practical solutions that deliver high-impact for customers, and working within a team of innovative researchers and engineers, this role is for you., * Outcome Driven Development: Work in a team developing and implementing advanced products that enable customers to post-train models to power their agentic coding practices. These agents need to generate high-quality code that meets their enterprise standards and software development best practices.

 * Translate Prototypes to Products: Collaborate closely with researchers, research engineers, MLOps and engineers within the team to design hypotheses and experiments, iterate proofs-of-concept quickly and develop successful prototypes into cutting-edge products.
 * Subject Matter Expert: You will contribute and discuss ideas within our cross-disciplinary team, driving towards the next generation of coding model post-training for enterprises.
 * Spearhead Research & Innovation: Stay up-to-date with the latest LLM and agentic developments; you are driven by learning and teaching others. You will need to explain complex technical details and concepts to both technical and non-technical audiences.


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