Roadmap › 0. Fundamentals › Step 6
LLD
Low-Level Design (LLD) — Object Design, UML and Classic Problems in C#
How to turn requirements into classes — the LLD interview approach, identifying entities and responsibilities, UML class and sequence diagrams, applying SOLID and design patterns, designing APIs and database tables, concurrency in object design, and complete C# designs for parking lot, library management, elevator, vending machine, LRU cache, rate limiter, splitwise/expense sharing and movie ticket booking.
Interview priority:★ Must know High priority — asked in almost every interview, learn firstMedium asked regularlyLow good to know
Module 1: Foundations of Object Design
- 1.From requirements to classes — nouns, verbs and responsibilitiesBasic ★ Must know
- 2.UML class diagrams and sequence diagramsBasic ★ Must know
- 3.Applying SOLID and design patterns in LLDIntermediate ★ Must know
Module 2: Classic LLD Problems
- 4.Design a parking lotIntermediate ★ Must know
- 5.Design a library management systemIntermediate ★ Must know
- 6.Design an elevator system and a vending machine (State pattern)Advanced ★ Must know
- 7.Design an LRU cache and a rate limiterAdvanced ★ Must know
- 8.Design expense sharing (Splitwise) and movie ticket bookingAdvanced Medium
Next course in the roadmap: 7. C# Language — Basics to Advanced →