CORE SOFTWARE ARCHITECTURES (Must Know in 2025)
Category Architecture Why It's Important
Enforces separation of concerns, testability, scalability.
✅ Application Clean Architecture
Most modern .NET apps use this.
Simple, widely used in enterprise apps. Good starting
✅ Application Layered (N-Tier)
point for beginners.
Similar to Clean; focuses more on domain model at the
✅ Application Onion Architecture
core.
✅ System /
Microservices Core for scalable, independently deployable services.
Distributed
✅ System / Event-Driven Works well with microservices. Enables real-time and
Distributed Architecture (EDA) decoupled communication.
✅ System / Still relevant in many companies. Good for small to
Monolithic + Modular
Distributed mid-size apps.
Optional (For Used in high-scale systems. Learn basics, but not
CQRS + Event Sourcing
scale) always needed.
SOFTWARE DESIGN PRINCIPLES (You Must Know)
Principle Why Learn
Foundation for maintainable OOP code. Every dev/PM should
SOLID
understand this.
DRY (Don't Repeat Yourself) Prevents redundancy.
KISS (Keep It Simple, Stupid) Avoid overengineering.
YAGNI (You Aren't Gonna
Prevents unnecessary features.
Need It)
Separation of Concerns Enables modular design.
CORE DESIGN PATTERNS TO MASTER (By Type)
These are the only patterns you need to learn to be effective in most real-world .NET/C# or
enterprise systems in 2025.
1. Creational Patterns (Object Creation)
Pattern Use Case
Singleton One shared instance across app (e.g., logging, config).
Factory Method Flexible object creation without exposing logic.
Builder Creating complex objects step by step (e.g., DTOs, APIs).
2. Structural Patterns (Composition)
Pattern Use Case
Adapter Connecting incompatible interfaces (e.g., wrapping legacy code).
Decorator Adding responsibilities dynamically (e.g., logging, validation).
Facade Simplifying a complex subsystem (used in APIs, service layers).
3. Behavioral Patterns (Object Interaction)
Pattern Use Case
Strategy Switch between algorithms (e.g., different pricing models).
Observer Event handling, messaging (used in pub/sub, UI, EDA).
Mediator Centralized communication (used in complex UI logic, components).
Command Encapsulate requests (used in CQRS, undo/redo).
Book Combo: "Clean Architecture" + "Design Patterns in C#" + "Dependency Injection in .NET"
💡 Covers:
Clean Architecture + SOLID – Clean Architecture by Robert C. Martin
Design Patterns in C# – C# Design Patterns by Judith Bishop or the GoF book with examples
online
LLD + DI + Principles – Dependency Injection in .NET by Mark Seemann
Udemy Master Course: Architecture + Patterns in C# by Bhrugen Patel
Software Architecture Fundamentals" – Mark Richards & Neal Ford (architecture, principles)
"Design Patterns in C#" – Dmitri Nesteruk (all core GoF patterns)
"SOLID Principles in C#" – Steve Smith
"Architecting Applications for the Real World in .NET" – Dino Esposito
"Microservices Architecture" – Shawn Wildermuth
1. Best Books (Core Learning)
📘 1. "Clean Architecture" by Robert C. Martin (Uncle Bob)
Why: Teaches solid software architecture foundations (boundaries, layers, separation of
concerns).
Applies to: HLD and LLD.
📘 2. "Design Patterns: Elements of Reusable Object-Oriented Software" by GoF (Gang of Four)
Why: The classic book for 23 essential OOP design patterns.
Use with: C# implementation examples (see below).
📘 3. "Domain-Driven Design" by Eric Evans
Why: Teaches deep modeling and architecture for complex systems.
Applies to: Enterprise-level HLD + LLD.
📘 4. "Dependency Injection in .NET" by Mark Seemann
Why: Essential for LLD, IoC containers, and SOLID principles in .NET.
📘 5. "C# 12 and .NET 8 – Modern Cross-Platform Development" by Mark J. Price
Why: Includes real-world applications, architecture patterns, and .NET-specific tools.
🔹 2. Best Video Courses / Tutorials
🎓 1. Pluralsight – Software Architecture Fundamentals by Neal Ford & Mark Richards
Covers: Architecture roles, HLD, components, communication styles.
Skill Level: Intermediate to advanced.
🎓 2. Pluralsight – Design Patterns in C# by Dmitri Nesteruk
Covers: All GoF patterns implemented in C# with real examples.
🎓 3. Udemy – Software Architecture & Design Patterns in C#
Instructor: Bhrugen Patel (well-known in .NET space).
Covers: Clean code, SOLID, design patterns in C#.
🎓 4. YouTube – Nick Chapsas
Covers: Practical modern .NET, architecture patterns, performance, APIs.
Style: Hands-on and code-focused.
🔹 3. Best Practical Projects / GitHub Repos
💡 1. Clean Architecture Template by Jason Taylor
Use for: Implementing Clean Architecture + DDD in real-world apps.
💡 2. eShopOnWeb
Microsoft’s sample reference architecture using ASP.NET Core, DDD, SOLID, etc.
💡 3. Awesome .NET Architecture
Massive curated list of real-world systems using modern .NET.
🔹 4. Design Principles to Learn
SOLID – Core of OOP design.
KISS / DRY / YAGNI – Practical principles for clean code.
CQRS + Event Sourcing – For scalable systems.
DDD – Domain-driven thinking for real-world enterprise apps.
1. Low Level Design (LLD) from Basics to Advanced – Udemy
Instructor: Shrayansh Jain (Staff Engineer at PayPal)
Highlights:
o Comprehensive coverage of object-oriented principles and design patterns
o Real-world case studies like designing Splitwise, BookMyShow, and Parking Lot
systems
o Step-by-step guidance on approaching LLD problems
Language: Primarily Hindi, with some English content
Ideal For: Developers seeking a structured approach to LLD concepts
Link: Udemy Course
2. Low Level System Design [An Interview Perspective] – Udemy
Instructor: Abhishek Ghosh
Highlights:
o Focused on preparing for LLD interviews
o Emphasizes problem-solving techniques and trade-off discussions
o Teaches how to create class diagrams and write test cases
Language: English
Ideal For: Candidates preparing for system design interviews
Link: Udemy Course
High-Level Design (HLD) Courses
1. High Level Design (HLD) from Basics to Advanced – Udemy
Instructor: Shrayansh Jain
Highlights:
o Covers distributed systems, microservices, and system architecture
o Includes design patterns, scalability strategies, and real-world system designs like
WhatsApp and URL shorteners
o Discusses concepts like CAP theorem, load balancing, and database indexing
Language: Primarily Hindi, with some English content
Ideal For: Engineers aiming to understand system-level design concepts
Link: Udemy Course
1. Low Level Design (LLD) from Basics to Advanced – Udemy
o Instructor: Shrayansh Jain
o Highlights:
Covers OOP principles, design patterns (Creational, Structural, Behavioral),
and UML diagrams
Includes solutions to frequently asked LLD interview questions
Suitable for SDE1, SDE2, and experienced developers
o Language: Hindi
o Rating: 4.4/5 (619 ratings)
o Course LinkArchitectural
Digest+4Udemy+4Udemy+4lowleveldesign.io+6Architectural Digest+6Udemy+6
2. Grokking the Low-Level Design Interview Using OOD Principles – Educative.io
o Highlights:
Developed by FAANG engineers
Focuses on object-oriented design fundamentals
Includes real-world interview questions
o Course Link
3. Low Level System Design, Design Patterns & SOLID Principles – Udemy
o Instructor: Prateek Narang
o Highlights:
Emphasizes object-oriented design patterns and SOLID principles
Guides through building robust applications in real-world scenarios
o Course LinkUdemy
High-Level Design (HLD) / System Design Courses
1. System Design Live Course – GeeksforGeeks
o Instructor: Sandeep Jain (Founder & CEO of GeeksforGeeks)
o Highlights:
Interactive videos, quizzes, and placement assistance
Highly recommended by students and professionals worldwide
o Course LinkGeeksforGeeks
2. Grokking the System Design Interview – Educative.io
o Highlights:
Crafted to prepare individuals for system design interviews
Offers detailed structures for building modern system designs
Includes 26 hours of study material
o Course Link
3. Software Design and Architecture – University of Alberta (Coursera)
o Highlights:
Covers software design and architecture principles
Offered by a reputable university
o Course Link
