Mastering system design is your golden ticket to solving complex challenges, scaling systems, and impressing your peers (and interviewers!). This System Design Roadmap for 2025 will guide you through the essentials. It will cover low-level design (LLD) and high-level design (HLD). Additionally, it includes real-world design scenarios.

The Basics of System Design

Before jumping into the nitty-gritty, let’s build a strong foundation.

What is System Design?

System design involves defining the architecture, components, and modules of a system. It aims to meet both functional and non-functional requirements. Think of it as constructing a skyscraper. Every floor, room, and pillar has a role. You need to ensure it’s sturdy, efficient, and scalable.

System Design Components

1. Database: Stores all the data securely.
2. Servers: Handle requests and deliver responses.
3. APIs: Enable communication between components.
4. Load Balancers: Distribute traffic evenly.
5. Scalability Options: Vertical (bigger machine) or horizontal (more machines).

Scaling 101

• Horizontal Scaling: Add more servers.
• Vertical Scaling: Beef up your existing server.
  Example: Instagram uses horizontal scaling to manage its billions of users.

Load Balancers & Routing

Load balancers act as traffic cops, ensuring that no single server is overwhelmed.

• Latency: Time taken to process a request.
• Throughput: Number of requests processed per second.

Low-Level Design (LLD): Diving Deep into the Details

Low-Level Design is where you zoom in on individual modules and their interactions. Here’s what you’ll tackle:

What is LLD?

It involves designing classes, methods, and data flows within individual modules. It’s like detailing every wire and socket in a building.

Key Components of LLD

LLD Techniques

• Code Optimization: Minimize resource use.
• Unit Testing: Verify each module independently.
• CI/CD: Automate testing and deployments for faster releases.

Example: Use event-driven architecture to notify users about order updates in real-time (like Uber).

High-Level Design (HLD): Big Picture Thinking

High-Level Design is about understanding the overall architecture.

What is HLD?

It focuses on the system’s architecture and interactions between components. Think of it as the blueprint of your skyscraper.

Key HLD Concepts

1. Availability: Uptime of the system.
2. Reliability: Handling failures gracefully.
3. CAP Theorem: Balancing consistency, availability, and partition tolerance.

Caching & CDN

• Caching: Speed up responses by storing frequently accessed data.
• CDN (Content Delivery Network): Distribute content globally to reduce latency.

Example: Netflix uses CDNs to ensure buffer-free streaming.

Key Differences Between HLD & LLD

Do These Questions to Master System Design

• Design URL Shortening Service: Learn to handle billions of requests efficiently.
• System Design Netflix: Understand global scalability.
• Design WhatsApp Messenger: Focus on reliability and message delivery.

System Design Roadmap for 2025

➤ Basics of System Design

✅ What is System Design?
✅ Functional vs Non-Functional Requirements
✅ What are the Components of System Design?
✅ System Design Life Cycle | SDLC (Design)
✅ Structured Analysis and Structured Design
✅ System Design Strategy
✅ Database Sharding – Concept
✅ Horizontal and Vertical Scaling
✅ Load Balancer in System Design
✅ Routing Requests Through Load Balancer
✅ Latency and Throughput in System Design
✅ Object-Oriented Analysis and Design
✅ Difference Between Structured and Object-Oriented Analysis

➤ Low-Level Design (LLD)

✅ What is Low-Level Design (LLD)?
✅ Data Structures and Algorithms for System Design
✅ Event-Driven Architecture
✅ Difference Between Authentication and Authorization
✅ What is API Gateway?
✅ What is Data Encryption?
✅ Design Patterns
✅ Code Optimization Techniques
✅ Unit Testing
✅ Integration Testing
✅ CI/CD: Continuous Integration and Continuous Delivery
✅ Introduction to Modularity and Interfaces in System Design
✅ Data Partitioning Techniques
✅ Class Diagrams | UML

➤ High-Level Design (HLD)

✅ What is High-Level Design?
✅ Availability in System Design
✅ Consistency in System Design
✅ Reliability in System Design
✅ CAP Theorem
✅ Difference Between Process and Thread
✅ Difference Between Concurrency and Parallelism
✅ Load Balancer
✅ Consistent Hashing
✅ Content Delivery Network (CDN) in System Design
✅ Caching in System Design
✅ Cache Eviction Policies
✅ Message Queues
✅ Communication Protocols
✅ Network Protocols and Proxies in System Design
✅ Unified Modeling Language (UML)

➤ Interesting Problems to solve

✅ Design URL Shortening Service
✅ Design Dropbox
✅ Design Twitter
✅ System Design Netflix – A Complete Architecture
✅ System Design of Uber App – Uber System Architecture
✅ Design Book My Show
✅ Designing Facebook Messenger
✅ Designing WhatsApp Messenger
✅ Designing Instagram

🎯 This checklist is your ultimate guide to mastering system design in 2025. Tick them off as you learn, and let the architecture magic begin! ✨

Conclusion

System Design is your superpower for building scalable, efficient, and reliable systems. Master the basics. Dive into LLD. Zoom out for HLD. You’ll have the skills to ace interviews. You will impress your team and architect systems like a pro. Start your 2025 System Design Journey today!

FAQs

1. What is the difference between HLD and LLD?
HLD is high-level architecture; LLD focuses on detailed module design.

2. What is CAP Theorem in system design?
It states that a system can have only two of the three: consistency, availability, or partition tolerance.

3. Why are load balancers important?
They distribute traffic evenly across servers, preventing overload and ensuring uptime.

4. What is database sharding?
It’s a technique to split large databases into smaller, faster, and more manageable parts.

5. How do caching and CDN improve system performance?
Caching speeds up data retrieval; CDNs reduce latency by delivering content from servers closer to the user.