Archive
The Dual Write Problem in NoSQL: MongoDB, DynamoDB, and Cassandra
The Dual Write Problem: Why Two Writes Always Fail Eventually — and How to Fix It
ID Generation Strategies in System Design: Base62, UUID, Snowflake, and Beyond
Big O Notation Explained: Time Complexity, Space Complexity, and Why They Matter in Interviews
Probabilistic Data Structures: A Practical Guide to Bloom Filters, HyperLogLog, and Count-Min Sketch
How CDC Works Across Databases: PostgreSQL, MySQL, MongoDB, and Beyond
Redis Sorted Sets Explained: Skip Lists, Scores, and Real-World Use Cases
Write-Time vs Read-Time Fan-Out: How Social Feeds Scale
Two Pointer Technique: Solving Pair and Partition Problems in O(n)
Tries (Prefix Trees): The Data Structure Behind Autocomplete
Sliding Window Technique: From O(n·k) Scans to O(n) in One Pass
Merge Intervals Pattern: Solve Scheduling Problems with Sort and Sweep
In-Place Reversal of a Linked List: The 3-Pointer Dance Every Interviewer Expects
Fast and Slow Pointer: Floyd's Cycle Detection Algorithm Explained
DFS — Depth-First Search: Go Deep Before Going Wide
Cyclic Sort: Find Missing and Duplicate Numbers in O(n) Time, O(1) Space
Binary Search Patterns: Five Variants Every Senior Engineer Knows
BFS — Breadth-First Search: Level-by-Level Graph Exploration
Two Heaps Pattern: Find the Median of a Data Stream Without Sorting
Top K Elements Pattern: Find the Best K Without Sorting Everything
K-Way Merge Pattern: Merge K Sorted Sequences with a Min-Heap
LLM Model Selection Guide: GPT-4o vs Claude vs Llama vs Mistral — When to Use Which
Model Evaluation Metrics: Precision, Recall, F1-Score, AUC-ROC Explained
LLM Observability: Tracing, Logging, and Debugging Production AI Systems