Senior Research Scientist, Specialized Professional Intelligence

About the role

As a Senior Research Scientist you will be a key architect of the core AI systems powering our professional intelligence platform. You will focus on building next-generation agentic systems designed to perform complex, deep reasoning and high-fidelity inference over extremely large corpora of unstructured data.

What you should have

• MSc or PhD in Computer Science, Mathematics, Machine Learning, or a related quantitative field
• 6+ years of experience building, scaling, and productionizing complex machine learning systems, with a strong focus on processing unstructured text data at scale
• Experience with information retrieval techniques (classical and embedding-based), knowledge graphs, or named entity recognition/reconciliation over large datasets
• Experience building inference systems that use LLMs as building blocks, such as LLM-as-a-judge evaluation pipelines or ensemble-based estimators
• Experience building custom agent harnesses, mastering the nuances of context engineering, state management, and optimization for multi-step reasoning loops
• Strong proficiency in Python and modern software engineering best practices (architecture design, rigorous testing, CI/CD, and version control)
• Experience implementing robust evaluation frameworks and performance monitoring for complex, non-deterministic AI systems in production
• Demonstrated ability to lead multi-quarter technical projects from concept to deployment, including guiding and mentoring junior team members
• Excellent written and verbal communication skills (e.g., design docs, technical specs) with an ability to translate ambiguous product/domain problems into concrete engineering roadmaps
• Able to work in the Mountain View office at least 3 days per week to interface with the rest of the team

It’d be great if you had

• Deep interest in the potential transformative effects of advanced AI systems and commitment to ensuring their safe development
• Startup experience or a proven ability to iterate quickly, navigate high ambiguity, and parallelize experiments to optimize system performance
• Experience training, fine-tuning, or distilling models for specialized task performance or latency optimization
• Experience tailoring AI systems or complex software architectures to specific, highly regulated, or knowledge-intensive industries
• A track record of public technical contributions, whether through open-source artifacts, robust AI tools, or peer-reviewed publications at top-tier machine learning venues (e.g., NeurIPS, ICML, ICLR, ACL)
• A strong product sense and a passion for analyzing user behavior and feedback to proactively improve system accuracy
• A consistent history of designing and delivering performant solutions to complex software engineering problems

Pay

The US base salary range for this full-time position is $165,000 - $238,000 + bonus + equity + benefits. Within the range, individual pay is determined by work location and additional factors, including job-related skills, experience, and relevant education or training. Your recruiter can share more about the specific salary range for your location during the hiring process.

Equal Opportunity Workplace

At X, we don't just accept difference - we celebrate it, we support it, and we thrive on it for the benefit of our employees, our products and our community. We are proud to be an equal opportunity workplace and is an affirmative action employer. We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. We also consider qualified applicants regardless of criminal histories, consistent with legal requirements.