150 interview questions with a STAR answer framework for each one, in a printable 31-page PDF plus a CSV you can import into any flashcard or spreadsheet tool. Six sections: Behavioral (40), System Design (25), Python & Coding (30), Product Sense (20), Data & SQL (20), Culture Fit (15). Every question comes with S/T/A/R prompts showing what belongs in each part of your answer, plus a tip naming the detail that makes the answer land. Built for the loop that works: answer aloud in under two minutes, then compare against the framework and rebuild yours. Coding and SQL questions include the edge cases that break naive solutions; design questions include the capacity math and failure modes interviewers wait to hear. All 150 questions were written originally for this vault. Nothing is copied from any question bank or paid prep site, so the phrasing stays unfamiliar and you practice thinking instead of recalling a memorized answer. Includes interview-prep-vault.pdf (A4) and questions.csv.