একজন জাভাস্ক্রিপ্ট ফোকাসড সফটওয়্যার ইঞ্জিনিয়ার হওয়ার পূর্ণাঙ্গ রোডম্যাপ (বাংলায়)

1. Syntax & Semantics

Core Syntax Structure:

Variables (var, let, const)
Data Types (string, number, boolean, null, undefined, symbol, bigint)
Conditionals (if/else, switch)
Loops (for, while, do-while, for...in, for...of)
Functions (declaration, expression, arrow functions, IIFE)
Scope & Hoisting

Advanced Concepts:

Closures
Lexical scope
Execution context & Call stack
Event loop & Task queue (microtask vs macrotask)
Garbage Collection
Prototypes & Prototype Chain
this binding, call, apply, bind
ES Modules (import/export) vs CommonJS (require/module.exports)

2. Standard Library & Built-in APIs

Core Modules/APIs:

Array, Object, Math, Date, JSON
Map, Set, WeakMap, WeakSet
Promise, Symbol, Proxy, Reflect
Intl, URL, Blob, File, FormData
fetch, AbortController
setTimeout, setInterval, clearTimeout, clearInterval

Node.js Built-ins (if using Node):

fs, path, http, os, events, crypto, stream, util
process, child_process

3. Error Handling & Debugging

Error Types:

SyntaxError, TypeError, ReferenceError, RangeError, etc.

Handling Techniques:

try/catch/finally
Custom Error Classes
Graceful degradation

Debugging Tools:

Browser DevTools (breakpoints, step over, call stack, watches)
console.log, console.table, console.trace
Node.js Debugger (node inspect)
VS Code Debugging Configuration

4. Performance Optimization

Concepts:

Big O notation (time & space complexity)
Algorithm efficiency
Memory leaks and how to prevent them

Optimization Techniques:

Debouncing & Throttling
Lazy loading (code splitting, image defer)
Avoiding unnecessary re-renders (React)
Efficient DOM manipulation (virtual DOM, document fragments)

Tools:

Chrome Performance Profiler
Lighthouse
Web Vitals (FCP, LCP, TTI)

5. Design Patterns & Best Practices

Principles:

DRY (Don’t Repeat Yourself)
KISS (Keep It Simple, Stupid)
YAGNI (You Aren’t Gonna Need It)
SOLID (adapted to JS/OOP)
Separation of Concerns

Common Patterns:

Coding Practices:

Consistent naming conventions
Pure functions where applicable
Avoid global scope pollution
Commenting where necessary (not too much)

6. Asynchronous Programming, Concurrency & Parallelism

Concepts:

Event loop & Callback queue
Callback hell
Promises
Async/Await

Advanced Asynchronous Tools:

Promise.all, Promise.race, Promise.any, Promise.allSettled
Generators + async iterators
Web Workers
Node.js Streams

7. Tooling & Ecosystem

Package Management:

npm, yarn, pnpm
package.json structure
versioning & lock files

Build Tools:

Vite, Webpack, esbuild, Rollup
Babel (transpilation)

Code Quality:

ESLint, Prettier
Husky + lint-staged
Commitizen + conventional commits

Environment:

.env files & dotenv
Cross-env for environment variables

8. Testing & Deployment

Testing Types:

Unit testing (Jest, Vitest)
Integration testing
E2E testing (Playwright, Cypress)

Concepts:

Test Coverage
Mocks, Spies, Fakes
TDD / BDD

Deployment Knowledge:

Static Site Hosting (Vercel, Netlify)
CI/CD Basics (GitHub Actions, GitLab CI)
Docker (optional but helpful)

9. Project Experience

Soft Skills from Projects:

Writing maintainable, modular, scalable code
Git branching, rebasing, resolving conflicts
Writing documentation for others
Working in teams using PRs, Issues, Kanban
Estimating tasks, debugging in production

Hard Skills from Projects:

State management (Redux, Zustand, Context API)
API consumption (REST, GraphQL)
Authentication flows (JWT, OAuth2, Clerk/Auth0)
Form handling & validation (React Hook Form, Yup)

10. Language Internals & Execution Model

JS Runtime Environment:

Browser vs Node.js differences
Global Object, window vs global

Interpreter Model:

JIT Compilation (V8 engine)
Memory management and garbage collection
How closures preserve memory

Scope & Execution:

Call stack
Memory heap
Event loop
Callback queue, microtask queue

11. Software Architecture & System Design

Frontend Architecture:

Component-driven development
Atomic design principles
Micro Frontends

Backend/System Architecture:

Monolith vs Microservices (Node.js-based)
RESTful design, GraphQL schemas
Caching (Redis), Rate limiting

Database Design:

MongoDB (NoSQL) or PostgreSQL (SQL)
Indexing, Pagination, Joins (if applicable)

System Design Patterns:

Load balancer, CDN, reverse proxy
Pub/Sub architecture
WebSockets & real-time systems

12. Git & Collaboration Workflow

Core Commands:

clone, commit, push, pull, fetch, merge, rebase, stash

Branching Strategies:

Feature branches
GitFlow
Trunk-based development

Code Reviews & PRs:

Writing meaningful commit messages
Reviewing others’ code
Resolving merge conflicts

13. Security Best Practices

Frontend/Web:

Avoiding XSS, CSRF, Clickjacking
HTTPS & SSL
Content Security Policy (CSP)

Authentication:

JWT, OAuth2
Secure cookie management (httpOnly, sameSite)
Rate limiting & brute force protection

Node.js Specific:

Helmet.js, CORS
Validating user inputs (e.g. zod, joi)

14. Documentation & Communication

Code-level Docs:

JSDoc / TypeScript types
Readable, clean code > too many comments

Project-level Docs:

README, CONTRIBUTING.md
API Docs (Swagger/OpenAPI)

Soft Skills:

Explaining technical problems clearly
Active listening in team discussions
Writing technical posts or documentation

15. Domain Knowledge

Optional but Valuable:

E-commerce (cart, checkout, payment flow)
SaaS (multi-tenancy, subscriptions)
Real-time apps (chat, notifications)
Booking/reservation systems
Payment Gateway Integrations (Stripe, PayPal)

16. Learning Mindset & Adaptability

Stay Up to Date:

Follow changelogs (e.g. ECMAScript updates)
Read MDN, dev.to, JavaScript Weekly

Learn New Tools Quickly:

Adapt to React/Vue/Svelte depending on need
Learn a testing tool, a CI system, or a backend stack when needed

Growth Practices:

Build projects
Pair programming
Read others’ code

Git and Github Refresher