Low-Level Design: Logging Framework (OOP Interview)
6 min read Low-Level Design: Logging Framework A logging framework is a fundamental software engineering tool — and a frequently-asked OOP design question […] Read article
System Design
System Design
System Design Interview: Design a Distributed Search Engine
6 min read System Design: Distributed Search Engine A distributed search engine indexes documents and serves queries with sub-100ms latency at massive scale. Read article
System Design
Low-Level Design: Notification System (OOP Interview)
8 min read Low-Level Design: Notification System A notification system delivers messages to users via multiple channels (push, email, SMS, in-app). It must Read article
Algorithms
Union-Find (DSU) Interview Patterns (2025)
6 min read Union-Find (Disjoint Set Union) Interview Patterns Union-Find (DSU) solves the dynamic connectivity problem: given a graph where edges are added Read article
System Design
Low-Level Design: Task Scheduler / Job Queue (OOP Interview)
7 min read Low-Level Design: Task Scheduler / Job Queue A task scheduler executes jobs at specified times or with specified delays, tracks Read article
System Design
System Design Interview: Design a Distributed Message Queue (Kafka)
6 min read System Design: Distributed Message Queue (Kafka) A distributed message queue decouples producers (services that generate events) from consumers (services that Read article
System Design
Low-Level Design: Pub/Sub Event System (OOP Interview)
6 min read Low-Level Design: Pub/Sub Event System The Publish-Subscribe pattern is one of the most important OOP design patterns. It decouples event Read article
Algorithms
Interval Algorithm Interview Patterns (2025)
6 min read Interval Algorithm Patterns Interval problems appear constantly in coding interviews — at Google, Meta, Airbnb, and Uber. The key skill: Read article
System Design
Low-Level Design: Online Shopping Cart (OOP Interview)
7 min read Low-Level Design: Online Shopping Cart The online shopping cart is a fundamental e-commerce OOP design problem. It tests entity modeling Read article
System Design
System Design Interview: Design a Social Media News Feed
6 min read System Design: News Feed (Facebook / Instagram / Twitter) A social media news feed aggregates posts from a user’s network Read article
Algorithms
Dynamic Programming on Strings: LCS, Edit Distance, and Patterns (2025)
6 min read Dynamic Programming on Strings String DP problems are among the most common in technical interviews, especially at Meta, Amazon, and Read article
System Design
Low-Level Design: Elevator System (OOP Interview)
6 min read Low-Level Design: Elevator System The elevator system is a classic OOP interview problem testing state machines, dispatching algorithms, and clean Read article
Algorithms
Low-Level Design: Food Delivery System (OOP Interview)
9 min read Low-Level Design: Food Delivery System (OOP Interview) The food delivery system (DoorDash/Uber Eats style) is a rich OOP design problem Read article
Algorithms
Low-Level Design: Chat Application (OOP Interview)
8 min read Low-Level Design: Chat Application (OOP Interview) A chat application combines real-time messaging, user management, conversation threading, and notification delivery. It’s Read article
Algorithms
Low-Level Design: Vending Machine (OOP Interview)
6 min read Low-Level Design: Vending Machine (OOP Interview) The vending machine is a classic state machine design question. It tests whether you Read article