What is Low-Level Design Document?

A Low-Level Design document is a detailed technical document that elaborates on the high-level design specifications provided in the High-Level Design document. It serves as a blueprint for developers to understand how individual components of a system will be implemented and how they will interact with each other to fulfill the requirements outlined in the HLD.

The Low-Level Design Document typically include:

• Component Design: Detailed descriptions of each component or module of the system, including its purpose, functionality, interfaces, and dependencies.
• Data Structures and Algorithms: Specifications of data structures and algorithms used within the system, including their implementation details, complexity analysis, and rationale for selection.
• Database Schema: Design of the database schema, including tables, columns, relationships, constraints, and indexing strategies.
• Interface Definitions: Definitions of interfaces between different system components, including APIs, protocols, message formats, and data exchange mechanisms.
• Sequence Diagrams: Sequence diagrams illustrating the flow of control and data between system components during various scenarios or use cases.
• Class Diagrams: Class diagrams depicting the class structure of the system, including relationships, attributes, methods, and inheritance hierarchies.
• Deployment Diagrams: Deployment diagrams showing how system components will be deployed across hardware or cloud infrastructure, including servers, containers, networks, and load balancers.
• Error Handling and Exception Handling: Strategies for handling errors, exceptions, and edge cases within the system, including error codes, error messages, logging, and recovery mechanisms.
• Performance Considerations: Considerations for performance optimization, including caching strategies, concurrency control, load balancing, and scalability techniques.
• Security Considerations: Considerations for ensuring the security of the system, including authentication, authorization, encryption, data privacy, and protection against common security threats.