ADevGuide Read 1
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What Is Scalability? A Beginner's Guide for Developers
Learn what scalability means in software development, why it matters, and how vertical vs horizontal scaling work - with real-world examples.
30 min read
Structured learning path
System Design Foundations
Follow this series from the first concept to the final deep dive. Every article is arranged in the recommended reading order.
Start with article 1- Articles
- 11
- Study time
- 270 min
Your path
Read in order
11 focused lessons
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- Read 2
Horizontal vs Vertical Scaling Explained (Scale Out vs Up)
Horizontal vs vertical scaling explained: scale up vs scale out, trade-offs for cost, availability, and performance, plus real examples to choose confidently.
22 min read - Read 3
What Is Load Balancing and How It Works
What is load balancing? Learn how load balancers work, key algorithms, health checks, and Layer 4 vs Layer 7 trade-offs.
19 min read - Read 4
What Are Sticky Sessions in Load Balancing? (Session Affinity)
Sticky sessions (session affinity) keep a user on the same backend. Learn how they work, when to use them, and safer stateless alternatives.
22 min read - Read 5
What Is Caching? Why It Improves Performance
What is caching? Learn how caches work, cache hits/misses, TTL, and common strategies (browser, CDN, Redis) to speed up apps.
23 min read - Read 6
In-Memory Cache vs Distributed Cache Explained
Compare in-memory cache vs distributed cache: speed, scalability, consistency, and when to choose Redis over a local cache.
25 min read - Read 7
What Is a CDN? How Content Delivery Networks Work
What is a CDN? Learn how content delivery networks cache content at edge servers, reduce latency, and protect your origin from traffic spikes.
29 min read - Read 8
What Is a Reverse Proxy? How It Works (For Beginners)
What is a reverse proxy? Learn how it routes traffic, hides your origin, handles SSL termination, and differs from a forward proxy.
32 min read - Read 9
What Is High Availability? A Beginner's Guide
Learn what high availability means, how redundancy and failover work, and why uptime percentages like 99.9% matter for modern systems.
29 min read - Read 10
What Is a Single Point of Failure (SPOF)?
Learn what a single point of failure (SPOF) is, why it brings down entire systems, and how to eliminate it with redundancy and failover.
28 min read - Read 11
Stateless vs Stateful Architecture for Backend Interviews
Learn stateless vs stateful architecture for backend interviews: where state lives, scaling trade-offs, sessions, Redis, and failure recovery.
11 min read