Strategy, Factory & Observer Design Patterns Explained | Production reality | Software Architecture

One missing key took down an entire payment system. And that single mistake is the perfect way to learn the 3 most-used Design Patterns: Strategy, Factory, and Observer, with real production examples in C# / .NET and Typescript

In this video we don't treat Design Patterns like boring textbook definitions. We treat them like real production failures. Starting from a Friday-evening payment outage, we solve three actual engineering problems every backend developer hits: how to isolate behavior, how to control object creation, and how to let systems react without tightly coupling them. Every pattern comes with the problem, a real-world desi example, before/after code, and most importantly, when NOT to use it.

This is Part 1. If you're serious about the Developer to Architect transition, this series is for you.

Topics covered:
- Blast Radius: why one small failure can crash an entire tightly coupled system
- Strategy Pattern: isolating swappable behavior behind a clean contract
- Factory Pattern: centralizing object creation and the Simple Factory vs Keyed DI approach in modern .NET
- Observer Pattern: decoupling publishers from subscribers, and how it scales into event-driven systems like Kafka
- The Strategy vs Factory boundary that trips people up in system design interviews
- The Open-Closed Principle in practice
- When each pattern is the wrong choice (avoiding over-engineering)

Chapters:
0:00 The Production Outage & Blast Radius
3:07 Setup: The 3 Problems We Solve
4:34 Strategy Pattern
10:18 Factory Pattern
14:23 Observer Pattern
16:53 The Task.Run Production Warning
18:34 Recap & Part 2 Preview

🔗 Full working code (Before/After demos)
https://github.com/desiarchitect/design-patterns.git

🚀 Want to go from Developer to Architect? Join the waitlist
https://desiarchitect.com

💬 1:1 guidance, career roadmap, architect track
https://topmate.io/deepak_mishra36/

Part 2 covers Decorator, Adapter, Facade, and the most misused pattern of all, Singleton. Want it sooner? Comment "Comment Part 2".

If this was useful, drop a like and subscribe. It genuinely helps the channel.

Jo textbook mein nahi hai, wo yahan milega.
The Desi Architect.

#DesignPatterns #SystemDesign #SoftwareArchitecture

Видео Strategy, Factory & Observer Design Patterns Explained | Production reality | Software Architecture канала The Desi Architect