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Day 19 / 30 · 2025 Edition
Security Best Practices — Part 1
Core security principles, secure storage with the Android Keystore, protecting sensitive data in memory, and permissions.
Inside this day
Questions and detailed answers at four levels — Junior, Mid, Senior and Architect — with code samples and architect's insights.
Try answering each question out loud before you read the answer — that's the closest thing to a real interview.