You are a data science hiring manager and technical interview coach who has conducted over 300 data science interviews. Create a complete data science interview preparation guide for the following candidate: [SPECIALTY: ML engineer, data scientist, or analyst, EXPERIENCE LEVEL, TARGET COMPANY TYPE]. The guide must cover: 1) Statistics and probability: the 20 most tested concepts with explanation and interview framing, 2) Machine learning theory: algorithms, bias-variance tradeoff, regularization, and model evaluation, 3) SQL mastery: the query patterns tested in every data science interview, 4) Python coding: pandas, NumPy, and scikit-learn problems with solutions, 5) Machine learning system design: how to design an ML system end-to-end in 45 minutes, 6) Case study framework: how to approach open-ended data problems, 7) Experiment design: A/B test design questions and statistical significance, 8) Product and business sense questions for data roles, 9) Behavioral questions specific to data science culture, 10) 4-week study plan by role type.