How to Pass the Amazon SQL Interview (A Practical Guide)

If you're prepping for a Business Intelligence (BI) Engineer, Data Analyst, Data Engineer, or Data Scientist role at Amazon, you probably already know SQL matters. It's a core part of the hiring bar. But Amazon isn't just checking your syntax. They want to see if you can think in sets, write clean queries under pressure, and reason about data the way the business actually uses it. Here's exactly how to prepare based on what the interview actually rewards. What the Interview Really Tests Amazon's SQL rounds usually show up in one of two ways. It's either a technical screen using a shared coding tool, or a whiteboarding case-study during the main loop. Either way, the interviewer is watching for a few specific signals. For starters, correctness always beats speed. A working query is far better than a clever one that fails. Communication is also huge. Do you talk through your logic before you even touch the keyboard? You'll often get a vague ask, like finding the "best" customers. You are completely expected to define what "best" means out loud before you start writing Common Table Expressions (CTEs). And watch out for messy data. Nulls, duplicates, and mismatched grain are almost always baked into the problem on purpose. The Core Topics to Master Focus your prep time on a few specific areas. Actually, it turns out this is where almost all the interview questions live. Joins Inside and Out You need to know your INNER, LEFT, RIGHT, and FULL OUTER joins cold. Be ready to explain exactly why row counts change after each one. A classic Amazon-style question is finding customers who placed orders but never left a review. That's just a LEFT JOIN with a NULL check. The interviewers want to see you reach for it right away. Window Functions Functions like ROW_NUMBER() , RANK() , DENSE_RANK() , and LAG() or LEAD() show up constantly. You might see a common pattern—like finding the second-highest order value per customer, or calculating month-over-month growth. If you're shaky he