Python Internals: How dict Works, When Not to Use It, and NumPy Arrays vs Lists
Company: Jain Global
Role: Data Scientist
Category: Software Engineering Fundamentals
Difficulty: easy
Interview Round: Technical Screen
Overview: Two Python fundamentals from a systematic trading screen: explain how a Python dict is implemented under the hood and which scenarios it is poorly suited for, then compare NumPy arrays with Python lists. It tests hash-table mechanics, cost analysis, memory layout, vectorization, and practical choices for large numeric data.