#Fundamentals

High Level Design

API Design

What makes a good API — goals of scalability, extensibility, and ease of use, plus REST best practices and common design patterns.

High Level Design

Caching

How caching works, the five write strategies (read-through, cache-aside, write-through, write-around, write-back), eviction policies, and common pitfalls.

High Level Design

Content Delivery Networks (CDN)

What CDNs are, how they work with edge servers and origin servers, their benefits and challenges, and how to choose the right provider.

High Level Design

Consistency & Isolation in Distributed Systems

Consistency models (linearizable, eventual, causal, quorum), database transactions, and the four isolation levels — from read uncommitted to serializable.

High Level Design

Data Replication & Migration

Primary-replica replication, WAL and CDC, async vs sync vs semi-sync trade-offs, split-brain problem, write amplification, and zero-downtime migration strategies.

High Level Design

Database Selection Guide

A structured decision framework for choosing the right database — SQL vs NoSQL, CAP thinking, NoSQL types, and interview-ready justification templates.

High Level Design

Databases

What databases are, how data is stored and retrieved, in-memory vs disk trade-offs, and a tour of relational vs NoSQL data models.

High Level Design

Distributed Consensus with Paxos

Two-Phase Commit, how Paxos achieves consensus through majority agreement, and the multi-server write coordination protocol with log-line locking.

High Level Design

Idempotency in Distributed Systems

Why idempotency matters, how to implement idempotency keys in APIs and message queues, and the trade-offs of tracking duplicate requests.

High Level Design

Kafka

Kafka's architecture, core components, partitions, ISR-based durability, trade-offs, and when to use it over RabbitMQ or SQS.

High Level Design

Load Balancing

Load balancers, routing algorithms, Layer 4 vs Layer 7 balancing, health checks, and how traffic flows through a real system.

High Level Design

Message Queues

How message queues decouple producers and consumers, core components, edge cases like poison messages and duplicates, and popular implementations.

High Level Design

Microservices vs Monolithic Architecture

A side-by-side comparison of monolithic and microservices architectures across scalability, deployment, fault isolation, team structure, and when to choose each.

High Level Design

Networks

Network fundamentals for system design — OSI model, DNS, HTTP, TCP vs UDP, REST vs GraphQL, WebSockets, WebRTC, and video streaming protocols.

High Level Design

Observability in Distributed Systems

Logging, monitoring, anomaly detection algorithms, and root cause analysis techniques for distributed systems.

High Level Design

Rate Limiting: System Architecture

Why rate limiting matters, the Timer Wheel and Hierarchical Timer Wheel approach, and a full distributed rate-limiting architecture with request sharding.

High Level Design

Redis & Memcached

Redis architecture, use cases, failure modes and mitigations, design FAQs, and a Memcached comparison — everything needed for a caching deep-dive.

High Level Design

Scalability: The Basics

Core concepts of scalability — vertical vs horizontal scaling, components that improve it, and trade-offs every system designer must reason about.

High Level Design

Security in Distributed Systems

Authentication mechanisms (token-based, SSO, OAuth), authorization patterns (ACLs, rule engines), attack vectors, and how to secure CDN-delivered content.

High Level Design

System Design Trade-offs

Pull vs Push, Memory vs Latency, Throughput vs Latency, Consistency vs Availability, Latency vs Accuracy — every key trade-off with decision frameworks.

Low Level Design

UML Class Diagrams: The Ultimate Guide

A concise guide to the core relationships in UML Class Diagrams: Association, Aggregation, Composition, Inheritance, Realization, and Dependency, with clear definitions and real-world examples.

Low Level Design

Deep Dive into Low Level Design (LLD)

Dive into the world of Low-Level Design (LLD) with this comprehensive guide. Whether you're prepping for interviews or strengthening your system design skills, this blog covers it all — essential topics, must-practice questions, core design patterns explained with real-world analogies, and annotated sample code snippets. Perfect for developers aiming to write clean, scalable, and maintainable code.

Concurrency

Concurrency & Multithreading: The Complete Guide