AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 19 min readLLD for Parking Lot System: Designing a Smart GarageTLDR TLDR: A Parking Lot is the "Hello World" of Low-Level Design. It teaches Encapsulation (ParkingFloor hides its Min-Heap), Abstraction (PricingStrategy interface), Inheritance (BikeSpot/CompactSp00
AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 25 min readLLD for Movie Booking System: Designing BookMyShowTLDR TLDR: A Movie Booking System (like BookMyShow) is an inventory management problem with an expiry: seats expire when the show starts. The core engineering challenge is preventing double-booking u00
AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 29 min readImplement LLD for Parking Lot: Code WalkthroughTLDR: This is the code companion to the Parking Lot System Design post. We implement the core classes (ParkingLot, ParkingSpot, Ticket) in Java, apply the Singleton, Factory, and Strategy patterns, an00
AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 22 min readLLD for Elevator System: Designing a Smart LiftTLDR TLDR: An elevator system is a textbook OOP design exercise: ElevatorCar encapsulates its stop queue, ElevatorState polymorphically handles direction changes (State Pattern), and DispatchStrategy00
AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 25 min readLLD for LRU Cache: Designing a High-Performance CacheTLDR TLDR: An LRU (Least Recently Used) Cache evicts the item that hasn't been accessed the longest when it's full. The classic implementation combines a HashMap (O(1) lookup) with a Doubly Linked Li00
AAAbstract Algorithmsinabstractalgorithms.dev·Mar 9 · 22 min readLLD for URL Shortener: Designing TinyURLTLDR TLDR: A URL Shortener maps long URLs to short IDs. The core challenge is generating a globally unique, short, collision-free ID at scale. We use Base62 encoding on auto-incrementing database IDs00
AAAbstract Algorithmsinabstractalgorithms.dev·Feb 20 · 20 min readLLD for Tic-Tac-Toe: Designing an Extensible OOP GameTLDR: Tic-Tac-Toe looks trivial — until the interviewer says "make it N×N with P players and pluggable winning rules." The key design decisions: a Board abstracted from piece identity, a Strategy Patt00
AAAbstract Algorithmsinabstractalgorithms.dev·Feb 11 · 21 min readLLD for Ride Booking App: Designing Uber/LyftTLDR: A ride-booking system (Uber/Lyft-style) needs three interleaved sub-systems: real-time driver location tracking (Observer Pattern), nearest-driver matching (geospatial query), and dynamic pricin00
AAAbstract Algorithmsinabstractalgorithms.dev·Feb 11 · 12 min readStrategy Design Pattern: Simplifying Software DesignTLDR: The Strategy Pattern replaces giant if-else or switch blocks with a family of interchangeable algorithm classes. Each strategy is a self-contained unit that can be swapped at runtime without tou00
OFOluwaseyi Fatunmoleinfreecodecamp.org·Jan 27 · 13 min readHow the Factory and Abstract Factory Design Patterns Work in FlutterIn software development, particularly object-oriented programming and design, object creation is a common task. And how you manage this process can impact your app's flexibility, scalability, and maintainability. Creational design patterns govern how...00
