Younghoon Kim Blog

Feb 13, 202616 min read

Minor optimizations found in React source code

Small React source-level optimizations explained: Object.freeze in DEV, Hidden Class effects, branch ordering, and Smi/Double choices.

react

Feb 10, 20268 min read

ESM is asynchronous, so how is static analysis possible?

ESM can be asynchronous and still statically analyzable. This post explains why through the Construction, Instantiation, and Evaluation phases.

javascriptesm+1

Feb 01, 20265 min read

Why Map and Set are known to have better performance than Array

Why Map and Set often outperform Array: hash-based lookup complexity, insertion behavior, and traversal trade-offs including cache locality.

javascriptdata-structure+1

Jan 23, 20264 min read

Measure and improve the performance of the AI tool you created

Rather than judging the quality of AI tools solely by feel, we have a record of quantifying the extent of improvement through datasets and automatic scoring.

aiprompt-smith

Dec 20, 20255 min read

Why bundlers exist

In this article, we summarize why bundlers emerged, what a dependency graph is, and why Vite took a different approach.

bundlervite

Dec 01, 20257 min read

Attaching a RAG-based AI chatbot to an open source document site

A practical guide to adding a RAG chatbot to open source docs, covering model choice, retrieval pipeline design, and cost-aware operations.

aifirsttx

Deep Dive intoReact

Recent

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Archive

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Measure and improve the performance of the AI tool you created

Why bundlers exist

Attaching a RAG-based AI chatbot to an open source document site

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Measure and improve the performance of the AI tool you created

Why bundlers exist

Attaching a RAG-based AI chatbot to an open source document site

Deep Dive intoReact

Recent

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Archive

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Measure and improve the performance of the AI ​​tool you created

Why bundlers exist

Attaching a RAG-based AI chatbot to an open source document site

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Minor optimizations found in React source code

ESM is asynchronous, so how is static analysis possible?

Why Map and Set are known to have better performance than Array

Measure and improve the performance of the AI ​​tool you created

Why bundlers exist

Attaching a RAG-based AI chatbot to an open source document site

Measure and improve the performance of the AI tool you created

Measure and improve the performance of the AI tool you created