FAANG SQL Mock Interview That Got the Job (For Data Engineers)
Click here to learn SQL for FREE: https://my.dataengineeracademy.com/lo...
Click here to learn how to 3X your salary: https://dataengineerinterviews.com/op...
Click here for a free ebook on how to ace the data engineering interview: https://dataengineerinterviews.com/e-... Check out this video to learn how to land your next data role in less than 90 days: • How to Get Your First Data Role in Less Th...
This FAANG SQL mock interview helped Kevin land the job. Learn how he tackled tough SQL questions with confidence — from joins to data prep, this is must-watch practice for every aspiring data engineer.
✅ Real feedback. Real results. Real prep.
Ready to transition into data engineering? Click to book a call: https://dataengineeracademy.com/ytinvit
⬇️ Click below to explore our coursework ⬇️
https://dataengineeracademy.com/ytcou...
00:00:00 – Introduction and Apologies
00:00:31 – Candidate shares background and struggles with previous mock interviews
00:01:03 – Recap of past mock sessions and clarification about the process
00:02:02 – Candidate shares screen and explains SQL task setup
00:02:31 – Beginner Question: Find users with more than 5 transactions
00:03:13 – Explaining approach: COUNT rows in transaction table, then JOIN with user info
00:04:28 – Clarifies what qualifies as a transaction
00:06:47 – Starts query, tests logic, and troubleshoots JOIN issues
00:08:02 – Interprets logic and verifies filtering by transaction count
00:09:10 – Moves to Intermediate Question: Calculate positive vs. negative balances
00:10:01 – Realizes null handling needed, uses COALESCE
00:13:42 – Sets up grouped queries for balance types
00:15:37 – Learns balance should reflect sum of withdrawals from second table
00:17:02 – Clarifies that all amounts are withdrawals (no deposits)
00:19:42 – Confirms running total and correctness of logic
00:21:52 – Adjusts for accounts with no transaction history
00:25:54 – Candidate checks if remaining balances logic is sound
00:26:59 – Reviews CASE logic and grouping
00:29:44 – Asks for hint on LEFT JOIN logic issue
00:31:50 – Revises JOIN directions for accurate matching
00:35:04 – Learns difference between NULL and 0 in SQL math
00:36:48 – Advanced Question: Find users with 3 consecutive transaction days with 1 on the second day
00:39:39 – Uses LAG() and PARTITION BY to track consecutive dates
00:44:25 – Hits error using alias with window function, rewrites query
00:47:51 – Corrects ordering logic with descending dates
00:50:35 – Builds table to count transactions per day
00:52:09 – Coach suggests: clean up output, include names, review JOIN logic
00:54:09 – Candidate forgot join condition, corrects it
00:55:10 – Output is right but logic for 2nd-day filter still needs review
00:56:45 – Feedback Begins: Subqueries good, great communication, testing is solid
00:59:02 – Candidate asks if they passed the mock interview
00:59:16 – Coach confirms pass but emphasizes importance of ongoing SQL practice
01:00:21 – Action Items: Clean code formatting, review LEFT/RIGHT joins, inspect data more thoroughly
01:02:10 – Wrap-Up and Farewell