🏗️

Top 50 SOLID Principles Interview Questions & Answers (2026)

50 Questions 20 Beginner 20 Intermediate 10 Advanced

About SOLID Principles

Top 50 SOLID Principles interview questions covering SRP, OCP, LSP, ISP, DIP, and their application in software design. Companies hiring for SOLID Principles roles test this knowledge at every stage — from first-round screens that check the basics to final-round conversations about real-world trade-offs.

What to Expect in a SOLID Principles Interview

Expect a mix of conceptual and practical SOLID Principles questions: clear definitions and core-concept checks for junior roles, hands-on scenario questions for mid-level roles, and architecture or trade-off discussions for senior roles. Interviewers usually move from foundational topics toward the kind of problems you'd actually face on the job.

How to Use This Guide

Work through the SOLID Principles questions in order — Beginner, then Intermediate, then Advanced — so each concept builds on the last. Every question has its own page; bookmark the ones that trip you up and revisit them the day before your interview.

Curated by Tech Baithak Editorial Team · Last updated: May 2026

Beginner 20 questions

Core concepts every SOLID Principles developer must know.

01 What are the SOLID principles? 02 What does the Single Responsibility Principle (SRP) mean? 03 What does the Open/Closed Principle (OCP) mean? 04 What does the Liskov Substitution Principle (LSP) mean? 05 What does the Interface Segregation Principle (ISP) mean? 06 What does the Dependency Inversion Principle (DIP) mean? 07 Why are SOLID principles important in software development? 08 What is a "code smell" and how does it relate to SOLID? 09 Give an example of SRP violation. 10 How does OCP promote extensibility? 11 What is the difference between SOLID principles and design patterns? 12 What is tight coupling and how does it relate to SOLID? 13 What is loose coupling and why is it desirable? 14 How does SRP help with testing? 15 What is cohesion in software design? 16 How does ISP differ from SRP? 17 What is dependency injection? 18 How does DIP relate to dependency injection? 19 What is the role of interfaces/abstractions in SOLID? 20 What is a "god class" and which SOLID principle does it violate?

Intermediate 20 questions

Practical knowledge for developers with hands-on experience.

01 How would you refactor a class that violates SRP? 02 How does the Strategy pattern support OCP? 03 What are the conditions for LSP compliance? 04 How does ISP prevent "fat interfaces"? 05 What is the difference between DIP and dependency injection containers? 06 How does SOLID relate to GRASP principles? 07 How do SOLID principles apply to functional programming? 08 What are the trade-offs of strictly following SOLID? 09 How does OCP work with inheritance vs composition? 10 What is the Barbara Liskov quotation that defines LSP? 11 How does DIP improve testability? 12 What is "design by contract" and how does it relate to LSP? 13 How do SOLID principles apply to microservices? 14 What is cohesion vs coupling and how do SOLID principles address both? 15 How do you apply SOLID in a legacy codebase? 16 How does the Decorator pattern support OCP? 17 What is "interface pollution" and which principle prevents it? 18 How do SOLID principles relate to YAGNI and DRY? 19 How does SRP apply at the module/package level? 20 What are common misconceptions about OCP?

Advanced 10 questions

Deep expertise questions for senior and lead roles.

01 How do SOLID principles apply to domain-driven design? 02 How do you balance SOLID principles with pragmatic software development? 03 How does the Hexagonal Architecture (Ports and Adapters) apply DIP? 04 What is the relationship between SOLID and Clean Architecture? 05 How does LSP interact with covariance and contravariance in type systems? 06 How do SOLID principles apply to event-driven architectures? 07 What metrics can you use to measure SOLID compliance? 08 How do SOLID principles evolve in a growing codebase? 09 How do SOLID principles differ in dynamically-typed vs statically-typed languages? 10 How do you teach SOLID principles to a development team?

Back to All Topics 50 questions total