Java Senior Software Engineer - IDE Extension

AI overview

Engage in building the infrastructure for IDE Extensions that impact over 1 million active users while steering the evolution of AI-assisted coding.
Who is Sonar? Sonar helps prevent code quality and code security issues from reaching production, amplifies developers' productivity in concert with AI assistants, and improves the developer experience with streamlined workflows. Sonar analyzes all code, regardless of who writes it — your internal team, genAI, or third parties — resulting in more secure, reliable, and maintainable applications. Rooted in the open source community, Sonar’s solutions support over 30 programming languages, frameworks, and infrastructure technologies. Today, Sonar is used by +7M developers and 400K organizations worldwide, including the DoD, Microsoft, NASA, MasterCard, Siemens, and T-Mobile. We believe in developing great products that are supported by great internal teams and a strong culture.  We are highly committed to and obsessed with the company, users, each other, and our open source community. We have high standards and hold each other accountable for acting with positivity, dedication, thoughtfulness, empathy, and passion daily.  We are deliberate with our decisions with high clarity of intention. At the same time, we feel extreme urgency and move forward quickly.  And lastly, we are highly effective and operationally efficient. We operate collectively as One Team to accomplish our goals. At Sonar, CODE is more than just an acronym – it's a mindset that defines daily operations.  Why You Should Apply:  At Sonar, we’re a group of brilliant, motivated, and driven professionals working hard to help supercharge developers to build better, faster. Sonar helps to continuously improve code quality and code security while reducing developer toil. This means that developers can focus on doing more of what they love and less of what they don’t. Our solutions don’t just solve symptoms of problems – we help fix issues at the source – for all code, whether it's developer-written, AI-generated, or from third parties. We have a dynamic culture with employees worldwide and hub offices in the USA, Switzerland, the UK, Singapore, and Germany. Team members should be able to come to work every day, work on a product they are proud of, love what they do, and feel energized by their peers. With our roots deep in the open source community, we’re all about the mission: supercharge developers to build better, faster. The Impact You Will Have: At Sonar, our team owns the external development experiences, including the SonarQube IDE Extensions (VS Code, IntelliJ, Visual Studio) and the Sonar Model Context Protocol (MCP) server. With over 1 million active users, we operate at a scale few developer tools achieve. The tools we build here are on the critical path for the world’s most impactful engineering teams, having a tangible, high-stakes impact on the global software supply chain. We are navigating a massive industry shift from manually written to AI-co-authored code. As a Senior/Staff member of the IDE Experience squad, you will define the vision for this hybrid engineering future, architecting an "inner loop" that anticipates the needs of both human engineers and AI Agents. You will build the critical infrastructure that empowers the engineers to move fast, ensuring that all code is "born clean" and secure before a PR is ever opened. What You Will Do Daily:
  • Build the Real-Time Feedback Loop. You will design and implement intelligent guidance systems that proactively steer both developers and AI agents toward secure patterns. Your mission is to ensure that security flaws and architectural drift are eliminated before a PR is opened.
  • Lead the Technical Evolution. You’ll drive architectural decisions for the IDE Extensions and their backend. You will solve for hard constraints: managing memory and CPU footprint, providing low-latency responses, and ensuring we never block the UI thread to protect the engineer's flow state.
  • Architect the "Context Engine" for AI Agents. You will contribute to the development of the Sonar MCP Server and Sonar CLI, allowing local AI Agents (like Cursor, GitHub Copilot, Claude Code, etc.) to "ask" for project rules and security context before they generate code.
  • Champion a Unified Experience. You will ensure our tools feel "native" in every IDE while sharing a robust logic core. You will bridge the gap between platform-specific implementations (TypeScript/C#) and our shared backend (Java) to prevent feature fragmentation across the ecosystem.
  • Act as a Technical "Force Multiplier." Beyond writing code, you’ll mentor the squad through design reviews and collaborate with the Code Quality and Security teams to ensure our static analysis engine runs efficiently in a live, local environment.
  • The Experience You Will Need:
  • Deep Engineering Foundation. You have significant professional experience (typically 7+ years) in one of the following ecosystems: Java (JVM internals, IntelliJ Platform UI / Compose), TypeScript (Node.js, VS Code Extension API), C# (.NET, Visual Studio Extensibility). You are a specialist in one but capable of learning and contributing to the other as needed.
  • Systems-Level Thinking. You understand the complexities of asynchronous programming, concurrency, and Inter-Process Communication (IPC). Experience with LSP (Language Server Protocol) and/or MCP (Model Context Protocol) is a plus.
  • Product-Minded Engineering. You don't just "take tickets." You are passionate about the impact of your work. You proactively bring new ideas to the roadmap and care about "Zero Friction" flow, understanding that if we slow down the Agent or the Human, we constrain the value we add.
  • Vision for "Agentic" Coding. You understand that the role of the IDE is changing. You want to build the infrastructure that allows AI to be autonomous and safe.
  • Collaborative Leadership. You have experience guiding engineers toward technical excellence and enjoy fostering a culture of empathy, continuous learning, and "dogfooding" our own tools.
  • Why You Will Love It Here:
  • Our culture and mission set us apart. We have a dynamic work culture that values respect and kindness and embraces the right to fail (and get right back up again!). 
  • Great people make a great company. We value people skills as much as technical skills and strive to keep things friendly while still being passionate leaders in our domains. 
  • We have a flexible work policy that includes 3 days in-office and 2 days work-from-home each week for those located near our office locations; some locations such as Dubai, India, Japan and Australia operate fully remotely.
  • We have a growth mindset. We love learning and believe continuous education is critical to our success. In an ever-changing industry, new skills are necessary, and we're happy to help our team acquire them.
  • As the leader in our field, our products and services are as strong as our internal team members.
  • We embrace transparency with regular meetings, cascading messages and updates on the growth and success of our organization.

  • Benefits of Working With Sonar:
  • We encourage usage of our robust time-off allocations with 27 PTO days for our employees based out of the Geneva region, plus additional days based on seniority and circumstances.
  • We contribute 60% of the total cost for your pension; 13.5% to 15.5% of your base salary for savings; 2% for risk.
  • Generous discretionary Company Growth Bonus, paid annually.  
  • Commuting:Sustainable mobility options, including carpooling and the refund of 60% of the annual transportation subscription.
  • Global workforce with employees in 20+ countries representing 35+ unique nationalities.
  • We have an annual kick-off somewhere in the world where we meet to build relationships and goals for the company.

  • 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.

    All offers of employment at Sonar are contingent upon the precise 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.  

    Perks & Benefits Extracted with AI

    • Commuting benefits: Sustainable mobility options, including carpooling and the refund of 60% of the annual transportation subscription.
    • Paid Time Off: 27 PTO days for our employees based out of the Geneva region, plus additional days based on seniority and circumstances.

    SonarSource builds world-class products for Code Quality and Security, empowering dev teams of all sizes to solve coding issues within their workflows.

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