SQL
Intermediate
SQL Subqueries: Correlated, Scalar, and EXISTS Explained
Master SQL subqueries — scalar, column, table, and correlated subqueries. EXISTS vs IN performance, and when to use CTEs instead.
PHP
Advanced
System Design: Design a Rate Limiter for APIs
Design a distributed rate limiter — token bucket vs sliding window, Redis-backed implementation, API middleware, and handling distributed deployments.
SQL
Intermediate
MySQL Stored Procedures and Functions: Complete Guide with Examples
Learn MySQL stored procedures and functions — parameters, IF/CASE logic, loops, transactions, and the difference between procedures and functions.
SQL
Intermediate
SQL Window Functions: ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD Explained
Master SQL window functions — ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD with PARTITION BY. The most asked advanced SQL topic in data and backend interviews.
PHP
Advanced
System Design Interview: Design a Chat Application Like WhatsApp
Design a real-time chat system for 500 million users — WebSockets vs polling, Kafka message queue, Cassandra storage, presence service and push notifications.
Laravel Eloquent ORM: Relationships, Eager Loading and Query Builder
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SQL Window Functions: ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD Explained
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System Design Interview: Design a Chat Application Like WhatsApp
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PHP File Handling: Read, Write, and Manage Files
21 views
Git Conflict Resolution
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PHP Input Validation: Never Trust User Data
Jun 3, 2026
PHP Magic Methods: __construct, __get, __set, __toString and More
Jun 2, 2026
PHP Static Methods and Properties Explained
Jun 1, 2026
PHP Abstract Classes vs Interfaces: Know the Difference
May 31, 2026
PHP Arrow Functions and Closures Explained
May 30, 2026