System Design Foundations — How the Pieces Fit Together

Why This Summary Exists

System design is not about memorizing components.

It’s about understanding how ideas connect when systems grow, fail, and evolve under pressure.

Over the last few posts, we built the foundation step by step. This post ties those ideas into one mental map.

The Foundation Map

flowchart TB
    SD[System Design]

    LVT[Latency vs Throughput]
    SVP[Scalability vs Performance]
    HV[Horizontal vs Vertical Scaling]
    SPOF[Single Point of Failure]
    SS[Stateless vs Stateful]
    CS[Client–Server Model]

    SD --> LVT
    SD --> SVP

    SVP --> HV
    HV --> SPOF

    CS --> SS
    SS --> SPOF

    SS --> HV
    CS --> SVP

How to Read This Diagram

This diagram is not a sequence. It’s a relationship map.

• Latency vs Throughput explains why systems feel slow
• Scalability vs Performance explains why optimizations hit limits
• Horizontal vs Vertical Scaling shows how systems grow
• Single Point of Failure reveals what brings systems down
• Stateless vs Stateful explains why memory complicates scale
• Client–Server Model defines responsibility boundaries

Together, they explain why some systems survive growth — and others don’t.

The Core Insight

These concepts reinforce each other:

• Stateless systems make horizontal scaling possible
• Horizontal scaling reduces single points of failure
• Clear client–server boundaries enable statelessness
• Scalability decisions matter more than raw performance

This is the foundation mindset of system design.

Where to Go Deeper

Each idea above is explored individually here:

• Latency vs Throughput
  https://vivekmolkar.com/posts/latency-vs-throughput/

• Scalability vs Performance
  https://vivekmolkar.com/posts/scalability-vs-performance/

• Horizontal vs Vertical Scaling
  https://vivekmolkar.com/posts/horizontal-vs-vertical-scaling/

• Single Point of Failure
  https://vivekmolkar.com/posts/single-point-of-failure/

• Stateless vs Stateful Systems
  https://vivekmolkar.com/posts/stateless-vs-stateful/

• Client–Server Model
  https://vivekmolkar.com/posts/client-server-model/

A Closing Thought

If these ideas feel obvious now, that’s a good sign.

Strong foundations make complex systems feel natural instead of intimidating.