🧠 Core Goal
Write code that is easy to understand, extend, test, and maintain — across small scripts and large systems.
When programmers write logical, maintainable code in interviews, it shows:
- Structured thinking
- Communication clarity
- Consideration for edge cases
- Architectural awareness
In this section we will go over core concepts which helps write code which is logical and maintaiable.
Following are the core concepts which help software developers write a good code which is logical and maintainable.
Clean Code and Principles
- SOLID Principles
- DRY, YAGNI, KISS, and Law of Demeter
- Code Smells and Refactoring basics
Functions and Class Design
- Small functions, single responsibility
- When and how to use classes
- Avoiding God objects
- Dependency Injection (DI)
Design Patterns for Maintainability
- Design patterns
- Favor composition over inheritance
- Use interfaces/protocols effectively
Testing and Automation for Maintainability
- Unit testing, mocking, integration tests
- Code coverage
- Continuous Integration basics
Architecture and Long-Term Maintainability
- Layered architecture (e.g., Controller-Service-Repository)
- Domain-Driven Design (DDD) basics
- Modular Monolith vs Microservices
- Writing maintainable APIs