Crazy SQL Interview Problem for Senior Data Engineers | Cyclic Money Transactions

In this video, we solve a challenging SQL interview problem often asked for Senior Data Engineer and Analytics Engineer roles. Problem Statement Given a transactions table, identify all groups of users involved in a circular money flow where: ✔ Money starts from User A ✔ Passes through one or more intermediate users ✔ Returns back to User A ✔ All transactions occur within 1 hour ✔ Amount remains constant throughout the cycle ✔ No user repeats in the path except the starting user Concepts Covered • Recursive CTE • Graph Traversal using SQL • Cycle Detection • Path Building • Advanced SQL Interview Questions • Real World Fraud Detection Scenarios • SQL Server Solution This is a great problem to strengthen your recursive CTE skills and understand how SQL can be used to detect suspicious transaction patterns. If you want more such advanced SQL interview problems, subscribe to the channel and keep practicing. 🚀 script: create table transactions ( transaction_id int primary key, sender_id varchar(3) not null, receiver_id varchar(3) not null, amount int not null, transaction_time datetime not null ); insert into transactions values (1, 101, 102, 500, '2025-01-01 09:00:00'), (2, 102, 103, 500, '2025-01-01 09:10:00'), (3, 103, 101, 500, '2025-01-01 09:20:00'), (4, 201, 202, 1000, '2025-01-01 10:00:00'), (5, 202, 203, 1000, '2025-01-01 10:05:00'), (6, 203, 204, 1000, '2025-01-01 10:10:00'), (7, 301, 302, 1000, '2025-01-01 10:00:00'), (8, 302, 301, 1000, '2025-01-01 10:05:00'), (9, 401, 402, 500, '2025-01-01 09:00:00'), (10, 402, 403, 500, '2025-01-01 09:10:00'), (11, 403, 404, 500, '2025-01-01 09:20:00'), (12, 404, 401, 500, '2025-01-01 09:25:00'); Zero to hero(Advance) SQL Aggregation:    • All About SQL Aggregations | SQL Advance |...   Most Asked Join Based Interview Question:    • Most Asked SQL JOIN based Interview Questi...   Solving 4 Trick SQL problems:    • Solving 4 Tricky SQL Problems   Data Analyst Spotify Case Study:    • Data Analyst Spotify Case Study | SQL Inte...   Top 10 SQL interview Questions:    • Top 10 SQL interview Questions and Answers...   Interview Question based on FULL OUTER JOIN:    • SQL Interview Question Based on Full Outer...   Playlist to master SQL :    • Complex SQL Questions for Interview Prepar...   Rank, Dense_Rank and Row_Number:    • RANK, DENSE_RANK, ROW_NUMBER SQL Analytica...   #sql #dataengineer