Om's Brain

1. Core Concepts

1 min read

3️⃣ Core Fundamentals (Must Know)

1. Storage

Types:

  • Relational DB (tables)
  • Document DB (JSON)
  • Key-value store

Concepts:

  • ACID vs BASE
  • Choose based on access patterns

2. Scalability

  • Vertical → bigger machine
  • Horizontal → more machines

Techniques:

  • Sharding
  • Partitioning
  • Consistent hashing

3. Networking

Important Layers:

  • Application → APIs, WebSockets
  • Transport → TCP vs UDP
  • Network → Load balancer

4. Performance

Concepts:

  • Latency
  • Throughput
  • Bottlenecks

Optimization:

  • Caching
  • Efficient queries

5. Fault Tolerance

  • Failures are unavoidable

Techniques:

  • Replication
  • Redundancy
  • Failover

6. CAP Theorem

  • Choose between:
    • Consistency
    • Availability
    • Partition tolerance
  • Partition tolerance is always required

4️⃣ Key Components in Systems

Database

  • SQL or NoSQL both can scale
  • Choose based on:
    • Read/write patterns

Cache

  • Example: Redis
  • Fast access
  • Stores frequently used data

Trade-off:

  • Consistency issues

Message Queue

  • Enables async communication

Examples:

  • Kafka
  • RabbitMQ

Use Cases:

  • Handle traffic spikes
  • Decouple services

Load Balancer

  • Distributes traffic
  • Prevents overload

Blob Storage

  • Stores large files (images, videos)
  • Example: S3

CDN

  • Global cache layer
  • Faster content delivery

5️⃣ How to Prepare Effectively

Learning Approach

  1. Try problem yourself 🧠
  2. Identify gaps
  3. Research (Google / ChatGPT)
  4. Watch solution

Strategy

  • Don’t memorize → learn patterns
  • Focus on trade-offs
  • Practice mock interviews

Mindmap

Graph View