LLD provides the detailed "how" of the system, acting as a direct guide for developers to write code.
: Typically created by Solution Architects or senior developers. Input : Software Requirement Specification (SRS).
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 SDLC: - Software Development Life Cycle HLD LLD
: Overall system architecture, technology stack, and major modules (e.g., Database, UI, Security).
: Designing a chat app's HLD involves defining the Messaging Service, User Database, and Notification System. Low-Level Design (LLD): The Micro View LLD provides the detailed "how" of the system,
: 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
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)
: 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.