Senior Data Scientist

Varonis is looking for a Senior Data Scientist to build and optimize machine learning and LLM capabilities that tackle real cybersecurity challenges. This role focuses on taking models from research to production, working across teams to integrate ML and LLM-based features into scalable systems.

What you’ll do

• Analyze large, complex datasets to uncover patterns and trends that may signal potential security threats.
• Partner with cybersecurity researchers to understand emerging threats and develop solutions using advanced machine learning and data analytics.
• Design, develop, and evaluate ML and LLM-based solutions, including classification, NLP, and security-focused models, from experimentation through deployment.
• Develop and optimize LLM techniques, including prompting, retrieval, embeddings, RAG, and fine-tuning where appropriate.
• Create robust evaluation methodologies and experiments for both classification and LLM-based systems, using suitable metrics to measure model quality, accuracy, and performance.
• Stay current on advances in machine learning, NLP, and LLMs, and assess how new approaches apply to real-world cybersecurity problems.
• Collaborate with software and data engineers to integrate ML and LLM solutions into production environments.
• Own complex data science problems end to end, from defining the problem to implementing and evaluating solutions.

What you bring

• Bachelor’s degree in Computer Science, Engineering, Statistics, Mathematics, or a related field (Master’s or Ph.D. is a plus).
• 5+ years of hands-on experience in data science, machine learning, or a related field.
• Strong knowledge of machine learning and deep learning, with practical experience building and evaluating classification models.
• Hands-on experience in NLP and text classification, including NER, training and fine-tuning models, and applying both traditional ML and modern LLM-based approaches.
• Strong proficiency in Python; experience with PySpark and Databricks is a plus.
• Experience developing and evaluating LLM-based applications, including prompt engineering.
• Experience with embeddings, vector search, and vector databases.
• Experience working with commercial and open-source LLMs and frameworks, including OpenAI models and the Hugging Face ecosystem.
• Experience with model fine-tuning, RAG systems, and LLM-based classification.
• Experience working with highly imbalanced datasets, selecting evaluation metrics, and optimizing precision/recall trade-offs.
• Strong analytical and problem-solving skills, with the ability to evaluate and interpret complex data and experimental outcomes.
• Excellent communication and collaboration skills for effective work in a multidisciplinary team.
• A proven track record of delivering high-quality solutions in a fast-paced, dynamic environment.

Tools you’ll use

Python, PySpark, Databricks, NLP, NER, LLM, prompt engineering, embeddings, vector search, vector databases, OpenAI models, Hugging Face ecosystem, RAG, fine-tuning, classification, deep learning, machine learning.

Varonis invites you to check out its Instagram page for more insight into the culture: @VaronisLife.