All posts
React Basics #14: Performance optimization (memo / useMemo / useCallback)
Cover performance optimization with React.memo, useMemo, and useCallback, and clarify when to use these tools and when to avoid them.
Hardware Basics #5: Storage ② Layout and Connection — RAID and DAS / NAS / SAN
RAID (0, 1, 5, 6, 10) that bundles disks for speed and safety, and the three ways to attach disks to a server — DAS, NAS, SAN. How these concepts were repackaged into cloud storage like instance store, EBS, and EFS.
IT Literacy for Non-Developers #2: What Is an API? — The Promise That Lets Services Talk to Each Other
This post explains APIs, a term developers use constantly, without any code. It walks through how requests and responses follow a fixed format, and how external APIs like maps and payments work.
React Basics #13: Custom Hooks
Learn how to write custom hooks — the elegant tool for sharing logic between components — with walkthroughs of commonly used examples.
Hardware Basics #4: Storage ① Devices — HDD / SSD / NVMe and IOPS / Throughput / Latency
How HDD, SSD, and NVMe differ, and how to distinguish capacity from the IOPS, throughput, and latency so often conflated with it. Why cloud disk options like gp3 and io2 diverge, all in one pass.
React Basics #12: useContext
Learn the tool that solves prop drilling — the React Context API and the useContext hook.
Hardware Basics #3: Memory — RAM, the Hierarchy, and What Happens When Swapping Starts
What RAM is and why it is volatile, the memory hierarchy from registers to disk, and how performance falls off a cliff when memory runs short and the system spills to swap. Understand memory as behavior, not as a capacity number.
React Basics #11: Lifting state up
Learn the core pattern for sharing data between two sibling components: lifting state up.
Hardware Basics #2: CPU — Cores, Threads, Clock, Cache, and What a vCPU Really Is
The difference between cores and threads, why clock speed alone cannot compare performance, how cache governs speed, and what the cloud actually means by a vCPU. Understand the CPU as behavior, not as a spec sheet.
How Open Source Changed the World
Open source is software that publishes its source code so anyone can read it, modify it, and redistribute it. This article explains in plain terms how a movement that began with GNU and Linux grew into the foundation of all modern IT.
React Basics #10: useEffect
Learn how the useEffect hook works — the standard tool for handling side effects that interact with the outside world — and explore common patterns.
Hardware Basics #1: Four Resources That Run a Computer — CPU, Memory, Storage, Network
Why a server is slow or expensive almost always narrows down to one of four resources: CPU, memory, storage, network. This is the mental model that runs through the whole series — what each resource is and how they cooperate within a single request.