Articles

Learning path

React, from the inside out

Ten long-form guides for building a durable mental model of React, from rendering fundamentals to Server Components. Not written by me.

10 guides · about 8 hours · updated May 2026

1. 01React Rendering and Reconciliation InternalsA guided deep dive into how React turns state into UI, compares trees, and keeps updates responsive.45 min read
2. 02React Hooks and EffectsA practical mental model for hooks, renders, effects, closures, and React's update queues.60 min read
3. 03React State Management ArchitectureHow to choose where state lives, avoid contradictions, and scale shared state without unnecessary complexity.55 min read
4. 04React Data Fetching and Server StateA guide to remote data as a cache: query keys, stale data, mutations, optimistic updates, and Suspense.55 min read
5. 05React Performance ArchitectureA measured approach to rendering cost, memoization, concurrency, virtualization, and bundle size.55 min read
6. 06React's Event SystemHow synthetic events, delegation, propagation, portals, and event priority work in modern React.45 min read
7. 07React's Scheduler and LanesA guided tour of cooperative scheduling, update priority, lanes, and React's concurrent work loop.45 min read
8. 08React Error Boundaries and ResilienceWhat React catches, how it recovers, and how error boundaries contain failures in real applications.45 min read
9. 09React Suspense InternalsHow promises suspend rendering, boundaries reveal content, retries work, and transitions prevent jarring fallbacks.45 min read
10. 10React Server Components and the Server/Client BoundaryA clear model of Server Components, Client Components, serialization, streaming, and framework boundaries.30 min read

Execution model

How JavaScript evaluates code, tracks execution, resolves declarations, and converts values.

4 guides · newest first

1. JavaScript Type Conversion: Why '6' / '2' Is 3How JavaScript converts values to strings, numbers, and booleans, including coercion, NaN, truthy and falsy values, and the special behavior of plus.February 2025 · 15 min read
2. How JavaScript Keeps Track of Running CodeUnderstand execution contexts, the call stack, and how asynchronous code fits into JavaScript's single-threaded execution model.January 2025 · 14 min read
3. JavaScript Hoisting Does Not Move Your CodeWhat actually happens to var, let, const, function, class, and function-expression bindings before JavaScript evaluates a scope.January 2025 · 14 min read
4. How the JavaScript Engine Runs Your CodeFrom source text to bytecode and optimized machine code, with the runtime, call stack, heap, and garbage collector explained.December 2024 · 15 min read

Scope & closures

Bindings, lexical scope, closure memory, and the rules that decide where values come from.

6 guides · newest first

1. JavaScript Scope: How Names Find Their ValuesHow global, function, and block scope shape name lookup, lexical environments, scope chains, hoisting, shadowing, and ReferenceError behavior.February 2025 · 14 min read
2. var, let, and const: Bindings, Scope, and the TDZCompare var, let, and const through declaration setup, scope, redeclaration, reassignment, global behavior, and the Temporal Dead Zone.February 2025 · 14 min read
3. JavaScript Blocks, Scope, and ShadowingHow blocks group statements, how let and const create block scope, how shadowing works, and why some redeclarations are illegal.February 2025 · 14 min read
4. Global Scope and this: Look at the Call SiteHow global bindings, classic scripts, modules, strict mode, methods, arrows, constructors, and event listeners determine the value of this.January 2025 · 16 min read
5. More on Closures: Scope Chains, Privacy, and MemoryA deeper look at returned functions, lexical bindings, shadowing, private state, constructor closures, and garbage collection.January 2025 · 14 min read
6. Closures in JavaScript: The Function's BackpackHow functions remember lexical scope, retain changing bindings, and use that memory for counters, currying, memoization, and async code.November 2024 · 13 min read

Functions & composition

Callbacks, higher-order functions, and reusable ways to transform and combine behavior.

4 guides · newest first

1. Map, Filter, and Reduce: Transform, Select, CombineLearn how map, filter, and reduce work through numbers, user records, accumulator traces, and practical combinations.February 2025 · 15 min read
2. Higher-Order Functions: Stop Rewriting the LoopHow passing and returning functions separates repeated control flow from changing logic, with a circle calculator built step by step.January 2025 · 14 min read
3. JavaScript Functions Are Values with BehaviorA practical tour of declarations, expressions, names, parameters, returned functions, first-class behavior, and arrow functions.January 2025 · 15 min read
4. Callback Functions: JavaScript Calls You BackWhat callbacks really are, when they run synchronously or asynchronously, and how they shape timers, events, array methods, and closures.January 2025 · 14 min read

Async & concurrency

The event loop, scheduling, callbacks, timers, and how one thread coordinates many tasks.

5 guides · newest first

1. setTimeout, Closures, and the Famous Loop ProblemWhy delayed callbacks share one var binding, how let creates a binding per loop iteration, and how helper functions preserve each value.February 2025 · 15 min read
2. JavaScript Concurrency: One Thread, Many TasksHow JavaScript makes progress on timers, network requests, rendering, and user input without confusing concurrency with parallel execution.January 2025 · 15 min read
3. Callback Hell: When JavaScript Starts Leaning SidewaysHow dependent asynchronous callbacks create the pyramid of doom, scatter errors, surrender control, and how promises and async functions restore structure.January 2025 · 14 min read
4. JavaScript, the Browser, and the Event LoopHow browser APIs, tasks, microtasks, and the event loop let JavaScript handle delayed work without blocking the main thread.January 2025 · 15 min read
5. setTimeout Has Trust IssuesWhy a timer delay is a minimum, not an exact execution time, explained through the call stack and event loop.January 2025 · 8 min read