Web Development Intermediate
From writing code to engineering applications: deepen JavaScript and the browser, master async and APIs, add TypeScript, testing, security, performance, a Node.js backend, SQL, and ship a full-stack capstone.
80 lessons0 challenges~23.25 hoursBeginner — no experience needed
Prerequisite course:Web Development Beginner
Who this course is for
For graduates of Web Development Beginner (required prerequisite): you can already build responsive pages, use the DOM and events, fetch from an API, and commit with Git. This course teaches you to decide how to build — structure larger programs, handle asynchrony deliberately, test and debug like a professional, and connect frontend, backend, and database into one deployable application.
What you will be able to do
- Write advanced JavaScript: closures, modules, higher-order functions, and Map/Set
- Delegate events and build reusable, stateful browser components
- Drive async code deliberately: event loop, promises, async/await, cancellation
- Consume real APIs with fetch: pagination, filtering, loading and error states
- Engineer advanced responsive UI: container queries, custom properties, theming
- Type your programs with TypeScript: unions, narrowing, generics
- Collaborate professionally with Git: rebase, conflicts, pull requests
- Test and debug systematically: unit, integration, and browser debugging
- Diagnose and fix performance with measurement, not guesswork
- Defend against XSS, injection, and CSRF; handle secrets and CORS
- Build REST APIs with Node.js and persist data in PostgreSQL with SQL
- Ship a full-stack application: build, configure, deploy, and monitor
Modern JavaScript
The professional JavaScript layer: closures and modules, higher-order functions, Map/Set, destructuring, and error handling — applied through data transformation.
- Scope, Closures, and Why They Matterintermediate14 min read
- Functions as Values: map, filter, reduceintermediate13 min read
- Destructuring, Spread, and Restintermediate11 min read
- Modules: import/export and Code Organizationintermediate12 min read
- Map, Set, and Structured Dataintermediate11 min read
- Deliberate Error Handlingintermediate14 min read
- Checkpoint: Data Explorer Coreintermediate20 min read
Advanced DOM & Browser APIs
From one-off DOM calls to component thinking: event delegation, stateful components, dynamic forms, URL and History APIs, timers, and observers.
- How Events Really Travelintermediate13 min read
- Event Delegationintermediate14 min read
- Stateful UI Componentsintermediate15 min read
- Forms Worth Trustingintermediate14 min read
- URL & History: The State You Can Shareintermediate13 min read
- Timers & Observersintermediate14 min read
- Checkpoint: Component Logicintermediate20 min read
Asynchronous JavaScript & APIs
Make the single thread work for you: the event loop, promises and async/await, parallel and sequential strategies, fetch with loading/error states, pagination, and cancellation.
- The Event Loop: One Thread, No Waitingintermediate14 min read
- Promises from First Principlesintermediate15 min read
- async/await: Sequential Shape, Concurrent Powerintermediate15 min read
- Promise Combinators: Choosing a Strategyintermediate14 min read
- fetch in the Real Worldintermediate16 min read
- Cancelling Work: AbortControllerintermediate12 min read
- Checkpoint: Async Request Engineintermediate22 min read
Advanced CSS & UI Engineering
Engineer interfaces, not just style them: custom properties and theming, cascade layers, container queries, fluid type, advanced Grid/Flexbox, and motion with respect.
- Custom Properties & Themingintermediate15 min read
- Cascade Layers & Specificity Without Tearsintermediate13 min read
- Container Queries: Components That Adaptintermediate14 min read
- Advanced Grid & Flexboxintermediate16 min read
- Component States & Accessible Interactionsintermediate14 min read
- Motion With Mannersintermediate12 min read
- Checkpoint: UI System Logicintermediate18 min read
TypeScript Essentials
Types as design tools, not bureaucracy: inference, unions and narrowing, generics, unknown at the boundaries — and the errors types catch before runtime.
- Why Types Existintermediate13 min read
- Everyday Typesintermediate14 min read
- Unions & Narrowing: Modeling Realityintermediate15 min read
- Generics: Reuse With Type Safetyintermediate15 min read
- unknown, never, and Honest Boundariesintermediate12 min read
- Typing APIs & the DOMintermediate14 min read
- Checkpoint: Type-Safe Client Logicintermediate20 min read
Professional Git & Workflow
Git as a professional tool: history as a graph, branches that stay mergeable, recovery without panic, and a review-driven workflow your team can trust.
- Git Internals: History as a Graphintermediate20 min read
- Branching Strategies That Scaleintermediate18 min read
- Merge, Rebase, and Conflictsintermediate22 min read
- Recovering: Reset, Revert, Cherry-pick, Stashintermediate20 min read
- PRs, Code Review, Conventional Commitsintermediate20 min read
- Secrets, Environment Variables, and Repo Hygieneintermediate18 min read
- Checkpoint: Professional Workflowintermediate20 min read
Testing & Debugging
Professional verification: a testing pyramid you can actually build, test doubles that isolate behavior, and a debugging method that beats guesswork.
- Why Tests Exist (and What They're For)intermediate16 min read
- Assertions and Test Structureintermediate18 min read
- Test Doubles: Mocks, Stubs, Spies, Fakesintermediate20 min read
- A Debugging Method That Worksintermediate22 min read
- Observing Real Applicationsintermediate18 min read
- Checkpoint: Test & Repairintermediate20 min read
Web Performance
Performance as measurement, not folklore: the rendering pipeline, the network waterfall, and the diagnose-first discipline behind Core Web Vitals.
- How Browsers Render (and Where It Janks)intermediate20 min read
- The Network Waterfallintermediate20 min read
- Assets: Images, Fonts, Cachingintermediate18 min read
- JavaScript Execution Costintermediate18 min read
- Measuring: Core Web Vitals and Budgetsintermediate20 min read
- Checkpoint: Performance Diagnosisintermediate20 min read
Web Security Fundamentals
Defensive security for web developers: think like an attacker for ten minutes, then spend your career making their job harder — XSS, injection, authz, CORS/CSRF, headers.
- Threat Modeling: Think Like the Attackerintermediate18 min read
- XSS and Output Encodingintermediate22 min read
- Injection and Input Validationintermediate20 min read
- Authentication, Authorization, Sessionsintermediate22 min read
- CORS, CSRF, and Security Headersintermediate20 min read
- Checkpoint: Security Auditintermediate20 min read
Backend Fundamentals with Node.js
The other side of the request: HTTP servers, routing, middleware, REST design, and validation — the machinery behind every API you have consumed.
Databases & Full-Stack Development
Relational thinking: tables, keys, joins, transactions — then wiring frontend, API, and PostgreSQL into one honest application.
Production Web Applications
What happens after `git push`: builds, environments, deployment, DNS/HTTPS, logging, and the CI/CD loop that ships safely.
Capstone: Build from Requirements
No more tutorials. You receive requirements, you make the decisions — data model, API shape, UI structure, validation, security, tests — and you ship.