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Database Series: From Fundamentals to Scale

Databases are the backbone of every scalable system.
Whether you’re preparing for high-level design (HLD) interviews or building real-world distributed systems, understanding how databases work — and how they scale — is essential.

This series is structured to take you from basics → advanced → real-world case studies, so you can follow it like a course or jump directly to the topic you need.


Articles in This Series

1. Fundamentals

  1. Database Fundamentals
    Basics of relational vs non-relational databases, ACID vs BASE, and core terminology.
  2. SQL vs NoSQL
    Deep dive into relational vs non-relational models, use cases, and trade-offs.
  3. CAP Theorem & Consistency Models
    Understanding consistency, availability, and partition tolerance in distributed systems.
  4. Database Indexing
    How indexes speed up queries, different indexing techniques, and common pitfalls.
  5. Sharding vs Replication
    Core scaling strategies, when to use them, and their trade-offs.

2. Scaling & Advanced Techniques

  1. Database Scaling Patterns
    Vertical vs horizontal scaling, replication strategies, and sharding techniques.
  2. Specialized Databases
    Key-Value, Document, Wide-Column, Graph, Search, and Time-Series databases explained.
  3. Caching & Query Optimization
    How caching works, caching strategies, and query optimization best practices.
  4. Distributed Transactions & Patterns
    2PC, 3PC, Saga pattern, CQRS, and Event Sourcing.

3. Real-World & Interviews

  1. Polyglot Persistence & System Design Patterns
    Using multiple databases in a single system — real-world strategies.
  2. Case Studies
    How Instagram, WhatsApp, Netflix, and Uber solved database scaling challenges.
  3. Interview Guide: Databases in HLD
    How to approach database design in system design interviews, pitfalls, and checklists.

4. Deep Dive: Internals

  1. Database Internals
    Write-ahead logs, MVCC, B-Trees, LSM trees, consensus (Raft, Paxos), consistent hashing, and bloom filters.

How to Use This Series

  • Beginner? Start from Fundamentals (Articles 1–5).
  • Interview Prep? Focus on CAP, Scaling, Indexing, and Interview Guide.
  • Real-world Engineer? Jump into Scaling Patterns, Transactions, Case Studies, and Internals.

Further Reading

  • Designing Data-Intensive Applications — Martin Kleppmann
  • System Design Interview — Alex Xu
  • High Scalability Blog
  • Engineering blogs of Netflix, Uber, Airbnb, and Meta

Connect: LinkedIn

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