Node.js Course

Start the Node.js course with a complete roadmap from JavaScript runtime fundamentals to enterprise backend architecture, security, performance, and interviews.

Learn what Node.js is, why it is a runtime rather than a language, and how JavaScript, V8, Node.js APIs, and the operating system relate.

Understand why teams choose Node.js for I/O-heavy APIs, when it is a poor fit, and how it compares with other backend runtimes.

Compare browser JavaScript and Node.js: available APIs, missing DOM and window, modules, and security boundaries.

See how JavaScript, V8, Node.js bindings, libuv, the thread pool, and the operating system fit together.

Learn what the Node.js runtime provides: process, modules, buffers, streams, and I/O that browsers do not ship.

Understand V8's role: parsing, compiling, optimizing, and garbage-collecting JavaScript inside Node.js.

Install Node.js correctly, verify versions, and understand LTS versus current release lines for production.

Manage multiple Node.js versions with nvm or similar tools and pin engines for teams.

Write, run, and reason about a first Node.js script and a tiny HTTP server without Express.

Organize src, config, tests, and composition roots so Node.js services stay maintainable.

Run scripts with node, npm scripts, watch modes, and environment-specific entry points.

Use the Node.js REPL and command-line flags to inspect runtime behavior and debug quickly.

Load configuration from the environment, separate secrets from code, and fail fast on missing required values.

Learn why Node.js programs are split into modules and how encapsulation works at file boundaries.

Use require, module.exports, and exports, and understand wrapping and load order.

Use import and export in Node.js, including type module, file extensions, and interoperability notes.

Trace how Node.js resolves relative paths, node_modules, and package exports maps.

Know when to use node: core modules versus npm packages and how to import them safely.

Design custom modules with clear exports, no hidden I/O, and testable seams. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Understand that Node.js caches loaded modules and why singletons appear accidentally.

Load modules on demand with import() for optional features and startup slimming. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Understand npm as the package manager and registry client that installs and publishes JavaScript packages.

Read and write package.json fields: name, type, engines, scripts, and dependency ranges.

Use dependencies versus devDependencies and interpret semantic version ranges and lockfiles.

Install, update, and remove packages reproducibly with npm and review the resulting tree.

Use npm scripts as the team interface for start, test, lint, and migrate. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use npm audit thoughtfully, review publish rights, and reduce supply-chain risk. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Publish a scoped package with a clear public surface, files list, and version policy.

Use npm workspaces to share packages without inventing a distributed system. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Contrast blocking calls with asynchronous I/O and why Node.js favors non-blocking APIs on the request path.

Read error-first callbacks and know where they still appear in Node.js core history.

Recognize nested callbacks and how promises and async/await flatten control flow.

Create, chain, and settle Promises, including rejection paths. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use async/await for readable asynchronous Node.js code and understand returned Promises.

Handle rejections, avoid unhandledRejection, and classify operational failures. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use Promise.all, allSettled, race, and any with clear failure semantics. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Cancel outbound work with AbortController and timeouts so Node.js does not wait forever.

Explain the Node.js event loop as the coordinator that resumes JavaScript when I/O and timers are ready.

Connect event-driven I/O to Node.js scalability for many idle connections. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Separate the call stack, macrotask/callback queues, and microtask queue (Promises, queueMicrotask).

Walk the major libuv phases: timers, pending, poll, check, and close callbacks. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use process.nextTick carefully: it queues work before the event loop continues and can starve I/O.

Compare setImmediate and setTimeout(0) and why order depends on context (inside I/O vs not).

Identify blocking JavaScript and synchronous I/O that stall the event loop. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Classify work and choose async I/O, worker threads, or another service accordingly.

Trace a complete turn: JS runs, microtasks drain, phases run, process stays alive while handles exist.

Use process for env, arguments, signals, exit codes, and runtime information. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use path, os, and url for portable filesystem paths, host facts, and URL parsing.

Know EventEmitter as a core primitive and util for debugging and promisify. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use Node.js crypto for hashing, HMAC, random bytes, and understand sync versus async cost.

Schedule timers correctly and use assert for invariants in tests and trusted internals.

Understand Buffer as fixed-length binary in Node.js and why strings are not bytes.

Spawn processes for tools and isolate CPU work, with argument safety and timeouts.

Offload CPU-bound JavaScript to worker threads without treating them as a scaling silver bullet.

Use node:fs and fs/promises for files and directories with explicit error handling.

Read and write text and binary files safely, including flags and encodings. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Create directories, list entries, and read stats without trusting filenames. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Know when sync fs is acceptable (startup, CLIs) and why it is dangerous on servers.

Stream large files so memory stays bounded and clients can start reading early. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Design uploads with size limits, virus-scanning seams, and object storage rather than naive disk writes.

Explain why Node.js needed Buffer before Uint8Array was ubiquitous and how they interoperate now.

Consume readable streams and write with backpressure in mind. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use duplex and transform streams for protocols and incremental processing. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Understand pipe, pipeline, and why backpressure protects memory. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Compose pipeline() for production stream graphs with guaranteed cleanup. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Design HTTP APIs that stream responses for large or incremental data. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Create emitters, listen, and emit events with the Node.js events module. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use events for decoupling inside a process without pretending it is a distributed bus.

Name events, handle errors, and avoid unbounded listeners. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Find leaks from forgotten listeners and growing listener arrays. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Review HTTP methods, status codes, headers, and message bodies from a Node.js server viewpoint.

Use node:http to create servers and understand IncomingMessage and ServerResponse.

Bind ports, handle connections, and shut servers down gracefully. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Read headers safely, set content-type, and avoid header injection. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Route on method and pathname and parse query strings without a framework. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Read bodies with size limits and parse JSON as unknown. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Map errors to status codes and never leak stacks in production. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Apply resource-oriented design and stateless requests on Node.js APIs. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Name resources, nest carefully, and avoid deep obligatory trees. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Choose GET, POST, PUT, PATCH, DELETE and 2xx/4xx/5xx correctly. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Validate bodies and produce consistent response envelopes. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Page large collections and push filters to the data store. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Version APIs when breaking changes are required; avoid decorative versions. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Standardize error bodies and document APIs for consumers. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Define Express as a Node.js HTTP framework and contrast it with the http module. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

See app, router, middleware, and error middleware as layers above Node.js. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Declare routes, params, and routers without putting business logic in the router file.

Write middleware for cross-cutting concerns and keep it side-effect explicit. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use four-argument error middleware and map AppError to HTTP. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Split HTTP adapters from application services for testability. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Validate params and authorize after authentication, never as the only security control.

Place uploads and feature routers in a maintainable Express composition. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use TypeScript for contracts in Node.js services while staying honest about erasure.

Configure tsconfig, module settings, and a build that runs on Node.js. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Separate wire DTOs from domain models and map at the adapter. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Type services and repositories so Node.js I/O stays replaceable in tests. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Model typed errors and generic API envelopes without over-abstracting. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Validate unknown input with a schema library and only then treat values as domain types.

Connect Node.js to PostgreSQL or MySQL with drivers, not as a full SQL course. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use the MongoDB driver from Node.js with explicit schemas at the application layer.

Size pools, set timeouts, and avoid exhausting database connections. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use parameterized queries and transactions for multi-row invariants. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use Prisma or similar as a Node.js data-access tool, not as the domain model. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Evolve schemas with versioned migrations from Node.js CI. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Hide drivers behind repositories so services stay database-agnostic at the use-case level.

Define authentication as proving identity, distinct from authorization. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Store session identifiers in secure cookies and session data server-side or in Redis.

Use short-lived access tokens and rotating refresh tokens with revocation strategy.

Hash passwords with bcrypt or Argon2 asynchronously and never log them. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Resolve the current user from a session or token and attach a trusted identity object.

Use OAuth for delegated authorization and OIDC for identity, without inventing your own protocol.

Model roles and permissions in the Node.js service, enforced on every request. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Authorize actions on a specific course or enrollment, not only global roles. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Centralize authorization decisions in policy functions or a small engine. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Isolate tenants in queries and policies so IDs from one school never read another.

Map OWASP risks onto Node.js APIs and dependency practice. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Prevent SQL, NoSQL, command, and header injection with parameterization and allowlists.

Understand browser-related risks for Node.js APIs that serve cookies or HTML. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Stop hostile keys and ../ paths from escaping your intended objects and directories.

Load secrets from the environment and set security headers on HTTP responses. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Rate-limit authentication and expensive endpoints, preferably with a shared store.

Harden tokens, sessions, and error messages against account enumeration where required.

Pin dependencies, review install scripts, and monitor advisories for Node.js services.

Use Error objects, codes, and cause chains in Node.js. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Keep the process alive for operational failures; crash or alarm on programmer defects.

Define stable error codes for clients and operators. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Handle unhandled rejections and Express errors without leaking internals. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Return safe client errors and rich operator context with correlation IDs. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Log JSON with levels and avoid string concatenation as your only telemetry. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Propagate IDs across logs, outbound HTTP, and queues. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use RED/USE metrics and traces for Node.js latency and event-loop delay. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Expose probes that match Kubernetes semantics: live versus ready. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Instrument Node.js with traces, metrics, and context propagation conceptually. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Watch event-loop delay, memory, GC, and saturation, not only HTTP 200 rates. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Choose unit, integration, and end-to-end tests for Node.js services. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Unit-test pure logic and integration-test repositories against a real or test database.

Test HTTP contracts: status, headers, and error shapes. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Pick a runner and keep tests fast and isolated. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Mock time and I/O at seams; use fixtures for documents and users. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use contract tests between services and sparse e2e journeys. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Define latency, throughput, and event-loop delay as first-class Node.js metrics. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Detect loop delay from sync work, huge JSON, and accidental crypto sync. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Find leaks from caches without TTL, global arrays, and forgotten listeners. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Profile CPU and understand that V8 optimizations do not fix I/O waits. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use cluster or a process manager to use multiple cores, and workers for CPU, only after measurement.

Apply HTTP and application caching, gzip/brotli, and healthy pools. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Run stateless Node.js replicas behind a load balancer. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Cache to save time and downstream load, with an explicit invalidation story. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use process memory for tiny hot data and Redis for shared cache. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Implement cache-aside and document who deletes keys on write. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use Redis for sessions and rate-limit counters across Node.js replicas. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Move email, PDFs, and retries off the request path. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use a queue library on Redis without confusing it with Node.js core. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Distinguish queues versus logs and why they are not Node.js. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Retry with backoff and isolate poison messages. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Make handlers safe to run at least once. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Explain why exactly-once is a system property, not a Node.js switch. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Understand the WebSocket upgrade and full-duplex frames on a Node.js process. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use Socket.IO as a library on Node.js with rooms and fallbacks, not as the runtime.

Manage membership, heartbeats, and authentication on sockets. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Scale connections with sticky sessions or a pub/sub adapter. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Combine HTTP for commands with sockets for push, plus a durable event log when required.

Parse multipart with size limits and stream to storage. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Validate size and type with allowlists; do not trust Content-Type alone. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Store objects with generated keys and signed URLs, not public original names. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Quarantine uploads, scan asynchronously, then publish. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Choose modular monoliths before networks, and microservices only for independent change and scale.

Draw bounded contexts and put cross-cutting auth and routing at a gateway. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Choose sync APIs versus async events for coupling and latency. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Coordinate multi-service changes with sagas instead of distributed ACID by default.

Retry idempotent calls and open circuits when a dependency is down. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Propagate context and SLOs across Node.js services. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Organize Node.js code into layers or modules with one-way dependencies. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Invert dependencies so Node.js HTTP and DB adapters implement ports. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use bounded contexts and inject collaborators at the Node.js composition root. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Slice by feature and isolate tenant data in every query. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Share types and lint rules without creating a distributed monolith of libraries. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Load typed config at boot and keep secrets out of repositories. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Scale a Node.js box up or out, knowing the event loop still exists on each process.

Put TLS and routing at the proxy; keep Node.js processes interchangeable. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Scale data with indexes, replicas, and honest consistency, not only more Node processes.

Absorb spikes with queues and worker processes separate from the API. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Package Node.js with a non-root image and probes; Kubernetes is an orchestrator, not Node.js.

Build artifacts once and configure with environment at run. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Run Node.js and dependencies locally and in CI with Compose. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Test, scan, and deploy Node.js from a pipeline. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Use a process manager and drain HTTP on SIGTERM. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Roll instances behind a load balancer with readiness gates. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Deploy Node.js to a cloud with logs, secrets, and network policy as first-class. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Build the core learning API: courses, lessons, and progress on Node.js. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Design catalog, cart, and order APIs with idempotent checkout. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Issue sessions or tokens with rotation and audit logs. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Model cohorts, assignments, and grading workflows. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Persist messages and fan out over sockets. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Handle webhooks, idempotency, and ledgers without double charges. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Fan out email and push from events with templates and preferences. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Publish domain events and consume them from isolated Node.js services. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Add tenancy, roles, and audit to a Node.js SaaS. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Assemble config, probes, logs, auth, validation, and shutdown into one service. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.

Practice Node.js interview questions from runtime fundamentals through architecture trade-offs.

Check runtime, async, HTTP, security, and architecture knowledge with scenario questions.

Practice targeted exercises that compose HTTP, async I/O, validation, and tests. This Node.js lesson connects the idea to runtime behavior, production APIs, and TechLearningPro.