A blog about technology, programming, and life.https://thienlb.io.vn/https://thienlb.io.vn/en/posts/backend-notes/01-http-and-cors/https://thienlb.io.vn/en/posts/backend-notes/01-http-and-cors/Backend notes on HTTP from its core principles — messages, methods, status codes, caching, versions — and on CORS, the browser mechanism built on top of it.Tue, 06 Oct 2026 02:00:00 GMThttps://thienlb.io.vn/en/posts/testing-principles/03-non-functional-testing/https://thienlb.io.vn/en/posts/testing-principles/03-non-functional-testing/Functionally correct software can still fail in production. Performance, data volume, stability, reliability, scalability and security each answer a different question.Sun, 20 Sep 2026 02:00:00 GMThttps://thienlb.io.vn/en/posts/testing-principles/02-software-component-integration-testing/https://thienlb.io.vn/en/posts/testing-principles/02-software-component-integration-testing/Functional Testing: Integration tests are not bigger unit tests. Black box, walking skeleton, Gherkin, Docker Compose — and which risks belong to which layer of testing.Sat, 19 Sep 2026 02:30:00 GMThttps://thienlb.io.vn/en/posts/testing-principles/01-functional-testing-unit-test-tdd-and-specification/https://thienlb.io.vn/en/posts/testing-principles/01-functional-testing-unit-test-tdd-and-specification/Three test layers and the pyramid, why 100% coverage still ships bugs, and how TDD, BDD and USDD differ in workflow but share one idea: define behaviour first.Sat, 19 Sep 2026 02:00:00 GMThttps://thienlb.io.vn/en/posts/design-patterns/03-wrapping-and-connecting-objects/https://thienlb.io.vn/en/posts/design-patterns/03-wrapping-and-connecting-objects/Adapter, Facade, Proxy and Decorator look almost identical in code. This post puts the comparison table first, then goes through each one, plus Composite, Bridge and Flyweight.Sat, 05 Sep 2026 02:10:00 GMThttps://thienlb.io.vn/en/posts/design-patterns/02-design-pattern-for-creating-objects/https://thienlb.io.vn/en/posts/design-patterns/02-design-pattern-for-creating-objects/An introduction to common Design Patterns for creating and initializing objects, and how to recognize when to use them.Sat, 05 Sep 2026 02:05:00 GMThttps://thienlb.io.vn/en/posts/design-patterns/01-design-patterns-and-principles/https://thienlb.io.vn/en/posts/design-patterns/01-design-patterns-and-principles/Most pattern guides teach you what a pattern is. The harder half is knowing when applying one makes your code worse.Sat, 05 Sep 2026 02:00:00 GMThttps://thienlb.io.vn/en/posts/software-engineering/logging-system/01-logging-systems-overview-and-design/https://thienlb.io.vn/en/posts/software-engineering/logging-system/01-logging-systems-overview-and-design/Logs have traditionally been created for developers to read and debug. But what if AI could understand what is happening in those logs too? A well-designed logging system can become the foundation for AI to investigate issues, understand the system, and help drive continuous improvement.Thu, 03 Sep 2026 03:00:00 GMThttps://thienlb.io.vn/en/posts/ai-coding/01-do-we-need-extra-layers-to-save-tokens/https://thienlb.io.vn/en/posts/ai-coding/01-do-we-need-extra-layers-to-save-tokens/More and more tools claim they cut token usage by 60–90% on AI coding tools. Before putting another layer between you and the tool, there are a few things worth weighing: output quality, security, and where those numbers actually came from.Tue, 25 Aug 2026 03:00:00 GMThttps://thienlb.io.vn/en/posts/chuyen-nghe-go-phim/01-my-journey-into-software-engineering/https://thienlb.io.vn/en/posts/chuyen-nghe-go-phim/01-my-journey-into-software-engineering/Four years of Business Administration, six months in Sales, then realising I belonged on the technical side — and deciding to learn Software Engineering again from close to zero.Sat, 22 Aug 2026 03:00:00 GMThttps://thienlb.io.vn/en/posts/software-engineering/ai-assisted/01-mindsets-for-software-engineers-in-ai-era/https://thienlb.io.vn/en/posts/software-engineering/ai-assisted/01-mindsets-for-software-engineers-in-ai-era/When implementation becomes fast and cheap, the value of a Software Engineer comes from how they think, ask the right questions, and make decisions — not how much code they can write.Wed, 08 Jul 2026 03:00:00 GMT