System Design

Budding

Taking shape: it has structure and links, and is still tended often

·1 min read·Planted Feb 2026

On this page4 sections

Overview

System design principles and patterns for building scalable applications.

Key Concepts

Architecture Patterns

Microservices
Monolithic
Serverless
Event-driven

Scalability

Horizontal vs Vertical scaling
Load balancing
Caching strategies
Database sharding

Reliability

Fault tolerance
Redundancy
Monitoring
Disaster recovery

Closed permits calls until a failure threshold opens the circuit. Open rejects calls. After a reset timeout, half-open permits a trial; success returns to closed and failure returns to open and restarts the timeout. — Conceptual circuit-breaker state machine illustrating fault tolerance. Thresholds and retry timing depend on the system; the diagram supplies no measured performance claims or default settings. Original diagram based on Martin Fowler, Circuit Breaker.

Design Process

Requirements gathering
Capacity estimation
System interface design
Data model design
High-level design
Detailed design
Scalability considerations

Further reading

Martin Fowler
Circuit Breaker
Follow a circuit breaker’s closed, open and trial states to understand how it contains repeated failures.

Connected notes