Anti-patterns to avoid in LLD - System Design Exercise

Design: System Design Anti-patterns Awareness

Discuss common system design anti-patterns, their impact, and avoidance strategies. Out of scope: deep technical implementation details.

Functional Requirements

FR1: Identify common anti-patterns in system design and architecture

FR2: Explain why these anti-patterns cause problems

FR3: Provide guidance on how to avoid these anti-patterns in real projects

Non-Functional Requirements

NFR1: Focus on practical, realistic examples

NFR2: Use simple language accessible to beginners

NFR3: Cover anti-patterns relevant to scalable and maintainable systems

Think Before You Design

Questions to Ask

❓ Question 1

❓ Question 2

❓ Question 3

❓ Question 4

Key Components

Monolithic architecture

Tight coupling between components

Ignoring caching strategies

Overusing synchronous calls

Lack of proper data partitioning

Design Patterns

Modular design

Loose coupling

Caching patterns

Asynchronous communication

Database sharding and partitioning

Reference Architecture

Anti-patterns Awareness System

+---------------------+
| User / Learner      |
+----------+----------+
           |
           v
+----------+----------+
| Anti-patterns Guide |
+----------+----------+
           |
           v
+----------+----------+
| Examples & Solutions |
+---------------------+

Components

User Interface

Web or CLI

Allows learners to explore anti-patterns and their impacts

Anti-patterns Repository

Document or database

Stores descriptions and examples of common anti-patterns

Solution Suggestions Module

Logic layer

Provides alternatives and best practices to avoid anti-patterns

Request Flow

1. User requests information about a specific anti-pattern

2. System retrieves anti-pattern description and examples from repository

3. System presents problems caused by the anti-pattern

4. System suggests better design patterns or solutions

5. User reviews and learns how to avoid the anti-pattern

Database Schema

Entities: - AntiPattern { id, name, description, impact, example } - Solution { id, anti_pattern_id, description, best_practice } Relationships: - One AntiPattern has many Solutions

Scaling Discussion

Bottlenecks

Large number of anti-pattern entries causing slow retrieval

Complexity in linking anti-patterns to multiple solutions

Difficulty in updating content as best practices evolve

Solutions

Use indexing and caching for fast lookups

Design flexible schema to support many-to-many relationships if needed

Implement content versioning and easy update mechanisms

Interview Tips

Time: Spend 10 minutes explaining common anti-patterns, 15 minutes discussing their impact and avoidance, 10 minutes on examples and alternatives, and 10 minutes on scaling and maintenance.

Explain what an anti-pattern is and why it matters

Describe specific anti-patterns with real-world examples

Discuss the negative effects on system scalability and maintainability

Show understanding of better design alternatives

Highlight importance of continuous learning and updating design knowledge