The of the Software Development Life Cycle (SDLC) is where business requirements are transformed into a technical blueprint . This phase is split into two critical stages: High-Level Design (HLD) and Low-Level Design (LLD) . High-Level Design (HLD): The Macro View
: Internal logic of individual components, including classes, methods, data structures, and specific algorithms. Responsibility : Created by Designers and Developers . Input : The approved High-Level Design. SDLC: - Software Development Life Cycle HLD LLD
HLD serves as the architectural roadmap, defining "what" the system will do and how its major parts connect. The of the Software Development Life Cycle (SDLC)
LLD provides the detailed "how" of the system, acting as a direct guide for developers to write code. Responsibility : Created by Designers and Developers
: The LLD for a chat app would specify using AES encryption for messages and defining exact database columns like Message_ID and Timestamp . Comparison Table: HLD vs. LLD SDLC: - Software Development Life Cycle HLD LLD - image
: Designing a chat app's HLD involves defining the Messaging Service, User Database, and Notification System. Low-Level Design (LLD): The Micro View
: Typically created by Solution Architects or senior developers. Input : Software Requirement Specification (SRS).