AI Researcher - Post-Training

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.

Responsibilities

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; 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: 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; Explain complex technical details and concepts to both technical and non-technical audiences

Requirements

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; Expertise in post-training of large language models; Experience in policy optimization algorithms (e.g. GRPO, PPO); Experience in verifier-based RL frameworks (RLVR); Experience in supervised fine-tuning (SFT); Experience in data-centric AI methods, including synthetic data and curation; Experience in parameter-efficient fine-tuning (PEFT); Experience in preference and safety alignment; Experience driving research projects, delivering valuable findings and prototypes, and converting them into products; Excellent communication skills in English and a talent for explaining complex scientific topics clearly and concisely; Genuinely based in the location the role is posted

Nice to have

Rust; C#; C++; JS/TS; Java