Senior Data Scientist – Machine Learning & Analytics

About the role

Haystack News is seeking a Senior Data Scientist to lead the development of advanced algorithms that enhance content discovery and user engagement on its streaming news platform. You will apply statistical analysis, causal inference, and experimental design to drive measurable improvements in retention and overall product performance.

Key responsibilities

• Design and implement statistical and machine learning models to improve content recommendation.
• Collaborate with ML engineers to move models from prototype to production.
• Conduct deep data analysis to uncover insights that influence product strategy.
• Apply causal inference techniques to evaluate the impact of product changes.
• Develop new ML features using text, multimodal embeddings, and generative AI.
• Validate offline model performance with online A/B testing and analyze experiment results.

Required profile

• PhD or M.S. in Computer Science, Statistics, Economics, Operations Research or a related quantitative field.
• 5+ years of professional experience in data science or machine learning.
• 3+ years working on large‑scale online ranking or recommender systems.
• Strong background in statistical inference, hypothesis testing, power analysis, and experimental design.
• Proven ability to translate offline analysis into product decisions that improve online metrics.

Required skills

• Python (pandas, NumPy, statsmodels, scikit‑learn)
• LightGBM and XGBoost
• SQL (PostgreSQL, Snowflake)
• dbt and Airflow
• PyTorch or TensorFlow