Dont repeat your self

• “Don’t repeat yourself” (DRY, or sometimes “do not repeat yourself”) is a principle of software development aimed at reducing repetition of software patterns, replacing it with abstractions or using data normalization to avoid redundancy.

• The DRY principle is stated as “Every piece of knowledge must have a single, unambiguous, authoritative representation within a system”. The principle has been formulated by Andy Hunt and Dave Thomas in their book The Pragmatic Programmer. They apply it quite broadly to include “database schemas, test plans, the build system, even documentation”. When the DRY principle is applied successfully, a modification of any single element of a system does not require a change in other logically unrelated elements. Additionally, elements that are logically related all change predictably and uniformly, and are thus kept in sync. Besides using methods and subroutines in their code, Thomas and Hunt rely on code generators, automatic build systems, and scripting languages to observe the DRY principle across layers.

Rule of three (computer programming) (Links to an external site.)

• Rule of three (“Three strikes and you refactor”) is a code refactoring rule of thumb to decide when similar pieces of code should be refactored to avoid duplication. It states that two instances of similar code do not require refactoring, but when similar code is used three times, it should be extracted into a new procedure. The rule was popularised by Martin Fowler in Refactoring[1] and attributed to Don Roberts.

• Duplication is considered a bad practice in programming because it makes the code harder to maintain. When the rule encoded in a replicated piece of code changes, whoever maintains the code will have to change it in all places correctly.

minimum viable product (MVP)

is a version of a product with just enough features to be usable by early customers who can then provide feedback for future product development. means that developers potentially avoid lengthy and (ultimately) unnecessary work. Instead, they iterate on working versions and respond to feedback, challenging and validating assumptions about a product’s requirements.

SOLID 5 Principles:

• S Single-responsiblity Principle
• O Open-closed Principle
• L Liskov Substitution Principle
• I Interface Segregation Principle
• D Dependency Inversion Principle