Showing Posts From
System Design
Jason Yang · 13 May, 2026
The Liskov Substitution Principle in Java: why the classic Rectangle/Square example violates LSP, and how smaller interfaces or composition fix the design.
System Design
Jason Yang · 13 May, 2026
Apply the Open-Closed Principle in Java with the Strategy Pattern — add new behavior without editing core logic, shown with a payment-processing example.
System Design
Jason Yang · 13 May, 2026
DIP vs DI in Java: they work together but differ — DIP keeps logic depending on abstractions, DI supplies dependencies from outside. Explained with examples.
System Design
Jason Yang · 12 May, 2026
SOLID principles in Java explained with simple examples — SRP, OCP, LSP, ISP, and DIP, each with backend-focused code. The full series index starts here.
System Design
Jason Yang · 12 May, 2026
Dependency Inversion Principle in Java, explained with notification, payment gateway, Spring Boot, and testing examples.
System Design
Jason Yang · 12 May, 2026
The Interface Segregation Principle in Java: why one fat interface forces empty methods and UnsupportedOperationException, and how small focused interfaces fix it — with phone, printer, and backend examples.
System Design
Jason Yang · 12 May, 2026
The Liskov Substitution Principle in Java: why a subclass that breaks its parent's contract violates LSP, shown with bird, Flyable, and discount policy examples.
System Design
Jason Yang · 12 May, 2026
The Open-Closed Principle in Java: add new behavior without touching stable code, shown with payment methods, interfaces, and Spring Boot style examples.
System Design
Jason Yang · 12 May, 2026
The Single Responsibility Principle in Java: what 'one reason to change' actually means in practice, with backend service and Spring Boot style examples.
System Design
Jason Yang · 26 Apr, 2026
Fuzzy search in PostgreSQL with pg_trgm: the operators, the GIN vs GiST index decision, and the tuning that keeps autocomplete from breaking in production.
System Design
Jason Yang · 26 Mar, 2026
A practical Kafka testing strategy using Spring EmbeddedKafka and Python testcontainers. Learn how to test producers and consumers with real Kafka instead of mocks.
System Design
Jason Yang · 26 Mar, 2026
Implement a Kafka consumer in FastAPI with aiokafka: async processing, manual offset commit, error handling, and idempotency patterns for production.
System Design
Jason Yang · 26 Mar, 2026
Implement a Kafka producer in FastAPI with aiokafka (async-first): pydantic-settings, event schema design, lifecycle management, and production best practices.
System Design
Jason Yang · 26 Mar, 2026
Implement a Kafka producer and consumer in Spring Boot: KafkaTemplate, @KafkaListener, manual ACK, retry handling, and Dead Letter Topic best practices.
System Design
Jason Yang · 26 Mar, 2026
Set up Kafka locally with Docker Compose and design scalable topic naming: partition keys, debugging, and real-world best practices in one practical guide.
System Design
Jason Yang · 26 Mar, 2026
Kafka essentials for beginners: topics, partitions, consumer groups, and ACKs explained in a practical, easy-to-understand way — core concepts made simple.
System Design
Jason Yang · 20 Dec, 2025
PostgreSQL TIMESTAMP WITH TIME ZONE (timestamptz) normalizes everything to UTC and prevents timezone bugs that only surface in production. Here's why it should be your default and how to migrate safely.
System Design
Jason Yang · 16 Dec, 2025
Secure PostgreSQL by separating admin and app roles: SQL scripts for schema hardening and automated permissions, for Cloud SQL, AWS RDS, or self-hosted.
System Design
Jason Yang · 22 Nov, 2025
Rate Limiting vs Throttling: often used interchangeably but different — rate limiting controls user quotas, throttling protects system health. The key differences.
System Design
Jason Yang · 17 Nov, 2025
Reliability vs availability: reliability is how long a system runs without failing; availability is how much of the time it's up. Examples and how to raise each.
