Skip to content
Level

SonarSource

Research Engineer (f/m/d)

SonarSource is hiring a Research Engineer (f/m/d). It pays €90k-€160k a year and Level rates it ; you can apply on SonarSource.

Level's read on this job

  • Level rates this role Builds AI ●●●●: the job is building AI systems.
  • The posting mentions AI agents and fine tuning among its tools and skills.
  • Level classes it as a mid-level role.
  • SonarSource has 119 other open roles on Level.

AI in this role

ai-agentsfine-tuning

Position description

 

At Sonar, we are seeking an innovative Research Engineer to join our Data & Agentic team and pioneer the next generation of our code analysis and verification engines. You will be at the forefront of applying cutting-edge AI, advanced agentic workflow and static analysis techniques to complex source code. Your work will directly shape our core products—ensuring both AI-generated and developer-written code meets rigorous enterprise quality and security standards. If you are driven to turn state-of-the-art research into practical, high-impact solutions, this is the role for you.

 

 

What you will do

  • Create & Innovate: Actively participate in the conceptualization phase. Brainstorm novel ways to improve our products and provide immediate, practical feedback to steer exploratory research toward paths that are both impactful and engineering-feasible.
  • Develop Agentic Workflows: Design, prototype, and validate intelligent agentic systems and automated workflows that facilitate writing clean code, identifying root causes of system issues, and remediating complex bugs and vulnerabilities.
  • Develop Pragmatic Prototypes: Build hands-on prototypes that prove the viability and scalability of research concepts. Proactively identify engineering bottlenecks or scalability limits and propose effective mitigations early in the research phase.
  • Evaluate & Benchmark: Drive the rigorous evaluation of new product features. Construct high-quality datasets, define relevant success metrics, and implement comprehensive benchmarks leveraging Sonar’s existing IP alongside third-party and open-source AI tools.
  • Engineer Data Pipelines: Build and manage robust data pipelines to gather, process, and version massive code-centric datasets required for training and evaluating specialized models at scale.
  • Translate Prototypes to Products: Collaborate closely with engineering and product teams to integrate successful prototypes into Sonar's cutting-edge products, ensuring they meet the needs of our global user base.
  • Communicate and Evangelize: Clearly articulate and document complex technical concepts and research findings to both technical and non-technical stakeholders

Experience and qualifications

    Must have:

  • Advanced academic background in Computer Science, Machine Learning, or a related quantitative field.

  • Strong software engineering experience (minimum 2+ years in industry) with proficiency in Python and major modern programming languages.

  • Practical experience with modern agentic frameworks, software automation tools, and LLM architectures.

  • Experience of driving research projects from initial ideation to a demonstrable prototype with a high degree of autonomy.

  • Hands-on experience integrating third-party tools, program analysis frameworks, or open-source libraries into functional prototypes.

  • Proven experience in data handling: constructing high-quality datasets, defining objective success metrics, and building robust benchmarks for new solutions.

  • The ability to fast context-switch and maintain momentum across multiple concurrent, fast-moving research topics.

  • Excellent communication skills in English, with a talent for translating complex research findings into clear, actionable artifacts for product engineering squads.

  • Plus:

  • Background in static analysis: abstract syntax trees (ASTs), code security, bug detection, etc..

  • Familiarity with LLM techniques such as model fine-tuning, semantic search engines, etc.

  • Experience with large-scale data processing frameworks and cloud infrastructure (e.g. AWS). 

  •  

     

Additional comments

This role is based in Bochum. We are unable to consider candidates unwilling to be in Bochum, but we are willing to relocate the right candidate.

How we rate this

Research Engineer (f/m/d) at SonarSource rates 89 out of 100 for how much of the daily work is AI. That makes it Builds AI (AI Level 4 of 4). The level is about AI in the job, not seniority.

Classification

Builds AI. The job is building AI systems.

  1. ●●●● Builds AI80 to 100
  2. ●●●○ Works on AI60 to 79
  3. ●●○○ Uses AI40 to 59
  4. ●○○○ Little AI0 to 39

Levels come from how often the tools, models and workflows of the role are named in the posting itself. Read the description and count the AI tools, models and workflows it names.

Prepare for this job

Built from this posting and from similar jobs on Level.

Skills and AI tools this role asks for

AI agentsFine-tuning

Questions you could be asked

  1. How do you decide when an AI agent can act on its own versus asking for approval first?
  2. Walk me through fine-tuning a model: what data did you use, and how did you check the result?
  3. How would you decide a model or AI system is ready to ship?
  4. Tell me about a time a model underperformed in production. How did you find out, and what did you change?

Adapt your resume

  • List these exact terms on your resume: AI agents and Fine-tuning. An applicant tracking system matches the wording, not the idea.
  • Attach one line of real, concrete experience to at least one of them. A tool named with nothing behind it rarely survives a human read.
  • Lead with what you built, trained or shipped. This role is judged on the AI system itself, not the tools around it.

Want an expert to read your CV for this job?

Free. Send your CV and the role you want next. You get your review by email within 24 hours.

Get new research jobs (Builds AI ●●●●) by email

One email a week with the new research jobs (Builds AI ●●●●), each rated for how much AI is in the work. No recruiter spam, unsubscribe in one click.

Free. One email a week. Unsubscribe in one click.

Similar roles

Research roles that build AI, at other companies.

What kind of AI work fits you?

Answer 12 practical questions in about three minutes. Get a simple profile, the work it points to, and live roles to explore next.

Find my next step

More jobs at SonarSource

Related searches

Same AI level