LLD Dojo

Reference

Twenty-three patterns and five principles, by name, so a pattern is never a word you have to go and look up somewhere else.

Reading these counts toward nothing. They are reference, not curriculum.

The five principles

Dependency Inversion Principlecore · taught by C3Interface Segregation Principlecore · taught by C5Liskov Substitution Principlecore · taught by C6Open/Closed Principlecore · taught by C2Single Responsibility Principlecore · taught by C1

Creational patterns

Buildercore · taught by B3Factory Methodcore · taught by B2Singletoncore · taught by loggerAbstract Factoryoccasional · not in the corpus, closest is B2Prototypeoccasional · taught by A2

Structural patterns

Adaptercore · not in the corpus, closest is C5Compositecore · taught by file-systemDecoratorcore · taught by B7Facadecore · taught by C5Flyweightoccasional · taught by A2Proxyoccasional · not in the corpus, closest is B7Bridgerare · taught by C4

Behavioural patterns

Chain of Responsibilitycore · taught by B7Commandcore · not in the corpus, closest is B4Iteratorcore · not in the corpus, closest is D4Observercore · taught by B4Statecore · taught by B6Strategycore · taught by B1Template Methodcore · taught by B8Mediatoroccasional · not in the corpus, closest is C1Mementooccasional · not in the corpus, closest is B6Visitoroccasional · taught by A3Interpreterrare · appears nowhere in this corpus

What the labels mean

core — You should expect to meet this in an LLD round, and to be asked its name. Know the Java shape cold.

occasional — Turns up in specific problems. Worth recognising and being able to sketch, not worth drilling.

rare — Named in books and almost never wanted in an interview. Read once so the word does not surprise you, then move on.