https://www.harikesh.xyz/articles Long-form guides on how JavaScript and React actually work, by Harikesh Mishra. en https://www.harikesh.xyz/articles/processing https://www.harikesh.xyz/articles/processing From programs on disk to processes, CPU scheduling, context switches, and threads, with the connection to Node.js and libuv. Mon, 07 Sep 2026 03:30:00 GMT https://www.harikesh.xyz/articles/v8 https://www.harikesh.xyz/articles/v8 How Node.js extends JavaScript, how V8 executes and optimizes code, and how the engine manages memory. Thu, 03 Sep 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-data-fetching-server-state https://www.harikesh.xyz/articles/react-data-fetching-server-state A guide to remote data as a cache: query keys, stale data, mutations, optimistic updates, and Suspense. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-error-boundaries-resilience https://www.harikesh.xyz/articles/react-error-boundaries-resilience What React catches, how it recovers, and how error boundaries contain failures in real applications. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-event-system-internals https://www.harikesh.xyz/articles/react-event-system-internals How synthetic events, delegation, propagation, portals, and event priority work in modern React. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-hooks-and-effects-internals https://www.harikesh.xyz/articles/react-hooks-and-effects-internals A practical mental model for hooks, renders, effects, closures, and React's update queues. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-performance-architecture https://www.harikesh.xyz/articles/react-performance-architecture A measured approach to rendering cost, memoization, concurrency, virtualization, and bundle size. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-rendering-reconciliation-internals https://www.harikesh.xyz/articles/react-rendering-reconciliation-internals A guided deep dive into how React turns state into UI, compares trees, and keeps updates responsive. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-scheduler-and-lanes-internals https://www.harikesh.xyz/articles/react-scheduler-and-lanes-internals A guided tour of cooperative scheduling, update priority, lanes, and React's concurrent work loop. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-server-components-internals https://www.harikesh.xyz/articles/react-server-components-internals A clear model of Server Components, Client Components, serialization, streaming, and framework boundaries. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-state-management-architecture https://www.harikesh.xyz/articles/react-state-management-architecture How to choose where state lives, avoid contradictions, and scale shared state without unnecessary complexity. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/react-suspense-internals https://www.harikesh.xyz/articles/react-suspense-internals How promises suspend rendering, boundaries reveal content, retries work, and transitions prevent jarring fallbacks. Fri, 01 May 2026 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-type-conversion-and-coercion https://www.harikesh.xyz/articles/javascript-type-conversion-and-coercion How JavaScript converts values to strings, numbers, and booleans, including coercion, NaN, truthy and falsy values, and the special behavior of plus. Mon, 17 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/settimeout-closures-var-let-loop https://www.harikesh.xyz/articles/settimeout-closures-var-let-loop Why delayed callbacks share one var binding, how let creates a binding per loop iteration, and how helper functions preserve each value. Fri, 14 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-scope-how-names-find-values https://www.harikesh.xyz/articles/javascript-scope-how-names-find-values How global, function, and block scope shape name lookup, lexical environments, scope chains, hoisting, shadowing, and ReferenceError behavior. Tue, 11 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/var-let-const-and-temporal-dead-zone https://www.harikesh.xyz/articles/var-let-const-and-temporal-dead-zone Compare var, let, and const through declaration setup, scope, redeclaration, reassignment, global behavior, and the Temporal Dead Zone. Sat, 08 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-block-scope-and-shadowing https://www.harikesh.xyz/articles/javascript-block-scope-and-shadowing How blocks group statements, how let and const create block scope, how shadowing works, and why some redeclarations are illegal. Wed, 05 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/map-filter-reduce-transform-select-combine https://www.harikesh.xyz/articles/map-filter-reduce-transform-select-combine Learn how map, filter, and reduce work through numbers, user records, accumulator traces, and practical combinations. Sun, 02 Feb 2025 03:30:00 GMT https://www.harikesh.xyz/articles/how-javascript-keeps-track-of-running-code https://www.harikesh.xyz/articles/how-javascript-keeps-track-of-running-code Understand execution contexts, the call stack, and how asynchronous code fits into JavaScript's single-threaded execution model. Thu, 30 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-hoisting-does-not-move-code https://www.harikesh.xyz/articles/javascript-hoisting-does-not-move-code What actually happens to var, let, const, function, class, and function-expression bindings before JavaScript evaluates a scope. Mon, 27 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/higher-order-functions-stop-rewriting-the-loop https://www.harikesh.xyz/articles/higher-order-functions-stop-rewriting-the-loop How passing and returning functions separates repeated control flow from changing logic, with a circle calculator built step by step. Fri, 24 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/global-scope-and-this-call-site https://www.harikesh.xyz/articles/global-scope-and-this-call-site How global bindings, classic scripts, modules, strict mode, methods, arrows, constructors, and event listeners determine the value of this. Tue, 21 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-functions-values-with-behavior https://www.harikesh.xyz/articles/javascript-functions-values-with-behavior A practical tour of declarations, expressions, names, parameters, returned functions, first-class behavior, and arrow functions. Sat, 18 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/javascript-concurrency-one-thread-many-tasks https://www.harikesh.xyz/articles/javascript-concurrency-one-thread-many-tasks How JavaScript makes progress on timers, network requests, rendering, and user input without confusing concurrency with parallel execution. Wed, 15 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/callback-hell-pyramid-of-doom https://www.harikesh.xyz/articles/callback-hell-pyramid-of-doom How dependent asynchronous callbacks create the pyramid of doom, scatter errors, surrender control, and how promises and async functions restore structure. Sun, 12 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/callback-functions-javascript-calls-you-back https://www.harikesh.xyz/articles/callback-functions-javascript-calls-you-back What callbacks really are, when they run synchronously or asynchronously, and how they shape timers, events, array methods, and closures. Fri, 10 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/asynchronous-javascript-event-loop https://www.harikesh.xyz/articles/asynchronous-javascript-event-loop How browser APIs, tasks, microtasks, and the event loop let JavaScript handle delayed work without blocking the main thread. Tue, 07 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/closures-beyond-the-basics https://www.harikesh.xyz/articles/closures-beyond-the-basics A deeper look at returned functions, lexical bindings, shadowing, private state, constructor closures, and garbage collection. Fri, 03 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/settimeout-minimum-not-deadline https://www.harikesh.xyz/articles/settimeout-minimum-not-deadline Why a timer delay is a minimum, not an exact execution time, explained through the call stack and event loop. Wed, 01 Jan 2025 03:30:00 GMT https://www.harikesh.xyz/articles/how-javascript-engine-runs-code https://www.harikesh.xyz/articles/how-javascript-engine-runs-code From source text to bytecode and optimized machine code, with the runtime, call stack, heap, and garbage collector explained. Fri, 27 Dec 2024 03:30:00 GMT https://www.harikesh.xyz/articles/closures-function-backpack https://www.harikesh.xyz/articles/closures-function-backpack How functions remember lexical scope, retain changing bindings, and use that memory for counters, currying, memoization, and async code. Tue, 05 Nov 2024 03:30:00 GMT