KISS (Keep It Simple) in LLD - Architecture Diagram

System Overview - KISS (Keep It Simple)

The KISS principle means designing systems in the simplest way possible. It avoids unnecessary complexity to make systems easier to build, understand, and maintain. Simple designs reduce bugs and improve scalability.

Architecture Diagram

User
  |
Load Balancer
  |
API Service
  |
Cache
  |
Database

Components

User

user

Initiates requests to the system

Load Balancer

load_balancer

Distributes incoming requests evenly to API services

API Service

service

Handles business logic simply without extra layers

Cache

cache

Speeds up data access by storing frequently used data

Database

database

Stores persistent data in a straightforward manner

Request Flow - 9 Hops

User → Load Balancer

Load Balancer → API Service

API Service → Cache

Cache → API Service

API Service → Database

Database → API Service

API Service → Cache

API Service → Load Balancer

Load Balancer → User

Failure Scenario

Component Fails:Cache

Impact:Cache misses increase, causing more database queries and higher latency

Mitigation:System continues working by querying the database directly; cache rebuilds over time

Architecture Quiz - 3 Questions

Why does the system use a cache before querying the database?

A To store user credentials

B To reduce database load and speed up responses

C To replace the database entirely

D To balance load between servers

Design Principle

This system shows the KISS principle by using a straightforward architecture with minimal components. Each part has a clear, simple role, avoiding unnecessary complexity. This makes the system easier to understand, maintain, and scale.