Sonar enables organizations to ship agentic code with confidence. Code creation is abundant, but confidence is scarce. Our core platform, SonarQube, verifies over 750 billion lines of code every day, delivering agentic verification and governance for all code. Trusted by more than 7 million developers and 75% of the Fortune 100, including teams at Nvidia, ServiceNow, Booking.com, Goldman Sachs, AstraZeneca, and Ford Motor Company, Sonar enables organizations to reduce outages, improve security, and lower the cost and risk of agentic software development.
Founded in Geneva and now headquartered in Austin, Texas, Sonar has a global team working across offices and hubs, including Silicon Valley, London, Bochum, Barcelona, Singapore, Tokyo, and the Washington, D.C. area. At Sonar, we’re enabling enterprises to build agentic software factories that can move quickly while maintaining the control, consistency and evidence required to ship with confidence.
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.
What you will do
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.
Experience and qualifications
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.
The ideal candidate will have:
Additional comments
This role is based in Bochum. We are unable to consider candidates unwilling to be in this location, but we are willing to relocate the right candidate.
We're intentional about this. We believe the best teams are built in the room together. Three anchor days — Mondays, Tuesdays, and Thursdays — create the collaboration rhythm that makes a hub office worth having.
Candidates need to be genuinely based in the location the role is posted — if that's not where you are today, we're happy to support relocation for the right person.
We value diversity, equity, and inclusion
At Sonar, we believe that our diversity is our strength. We are a global company that values and respects different backgrounds, perspectives, and cultures. We are committed to fostering a diverse and inclusive work environment where everyone feels valued and empowered to contribute their best. We are proud to be an equal opportunity employer and welcome all qualified applicants, regardless of race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.
If you need any accommodation, please reach out to us at [email protected].
All offers of employment at Sonar are contingent upon the results of a comprehensive background check and reference verification conducted before the start date.
Applications that are submitted through agencies or third party recruiters will not be considered.
Skills Required
- Master's or PhD in Computer Science, Machine Learning, or related quantitative field
- 4+ years industry experience in machine learning
- Fluency with Python and core ML frameworks
- Experience with Rust or SonarQube flagship languages (C#, C++, JS/TS, Java)
- Expertise in post-training of large language models (policy optimization such as GRPO, PPO)
- Experience with 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
- Experience driving research projects and converting prototypes into products
- Excellent communication skills in English
- Must be based in Bochum (relocation supported for right candidate)
What the Team is Saying
.png)
.png)
Sonar Compensation & Benefits Highlights
-
Healthcare Strength — Healthcare coverage includes 90% employer-paid premiums for U.S. employees (60% for dependents), fully paid life and disability insurance, and 100% telemedicine for eligible employees. This breadth positions health protection as a clear standout in the package.
-
Leave & Time Off Breadth — Time off is described as 25 PTO days in the U.S. with additional days based on seniority or circumstances, while other sources cite roughly 18–23 days in practice. Overall, the vacation offering is portrayed as generous relative to common tech norms.
-
Retirement Support — Retirement benefits feature a 401(k) match up to 4% of gross salary in the U.S., with some postings noting day-one vesting. This provides a solid baseline for long-term savings support.
Sonar Insights
What We Do
Sonar provides the essential verification layer for the AI-driven development era, ensuring all code—whether human-written or AI-generated—is code you can trust. Today, AI coding tools are generating explosive volumes of code. This has created an "engineering productivity paradox" : faster code writing doesn't automatically lead to faster, safer software delivery. The new bottleneck is verification. Sonar solves this. Integrating code quality and code security into a single platform (SonarQube), Sonar is the foundation for high performance software engineering, analyzing over 750 billion lines of code daily to ensure applications are secure, reliable, and maintainable. As an independent verification platform, Sonar enables organizations to securely develop at the speed of AI. We are driven by a deep belief in our people, a commitment to excellence, and an unwavering dedication to delivery. We operate as a united group where our collective success is the sum of each individual's contributions. Our company culture is driven by the values of CODE: Committed, Obsessed, Deliberate & Effective. This mindset reflects our culture of creativity, collaboration, and pride in the work we do. Rooted in the open source community, Sonar’s solutions support over 35 programming languages, frameworks, and infrastructure technologies. Today, Sonar is used by 7M+ developers worldwide, including ServiceNow, Booking.com, Deutsche Bank, AstraZeneca, and Ford Motor Company. Sonar is headquartered in Geneva, Switzerland with additional offices in Austin, Texas; Bochum, Germany; London, Singapore, and Tokyo. The company is rapidly growing with over 800 employees! Join us in our mission to solve the trillion-dollar challenge of bad code!
Why Work With Us
We are a product-first company, with a people-first culture. Every employee has the opportunity to grow and learn. We promote from within, provide regular feedback and professional development opportunities, value the right to fail along with respect and kindness and work with team members to achieve their full potential.
Gallery
Sonar Offices
Hybrid Workspace
Employees engage in a combination of remote and on-site work.
At Sonar, we require employees to come into the office 3 days/week.
