Study Less LeetCode, More SQL: A Data Engineer's Smarter Interview Prep Guide

A data engineer writing for DEV Community argues that candidates are wasting hundreds of hours preparing the wrong material for technical interviews, having personally bombed a FAANG loop after 80 hours of LeetCode practice. Research cited in the article suggests 35 to 50 problems is sufficient for most data engineering roles, with trees, graphs, and dynamic programming largely irrelevant to actual interview questions. Meanwhile, SQL fluency — particularly window functions — appears in 69 to 79% of DE job postings and 85% of full interview loops, making it far more valuable to master. Major tech companies including Airbnb, Meta, and Google have already shifted their interview formats away from isolated algorithm puzzles toward pipeline design and real-world coding scenarios. The author contends that the widening gap between what LeetCode tests and what data engineering roles actually require is costing candidates job offers they would otherwise be qualified to receive.