Stage 3: Backend Essentials

Course Overview

This course takes you from your first node app.js to a REST API with persistent storage. It covers the runtime, the standard library, npm, Express and the patterns every backend is built from — 6 lessons, each with a runnable example and an assignment.

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Prerequisites

• JavaScript fundamentals: variables, functions, arrays, objects, async/await
• Comfort with the terminal
• Node.js 20 or newer and npm installed
• VS Code (recommended)

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Lesson List

Lesson	Title	Key Topics
Lesson 01	Node.js Basics	runtime, REPL, CommonJS vs ESM, process.argv, exit codes
Lesson 02	Built-in Modules	fs, path, os, EventEmitter, sync vs async
Lesson 03	npm Packages	package.json, dependencies, npx, nodemon, dayjs, .gitignore
Lesson 04	Express Basics	routing, middleware, static files, 404 handling
Lesson 05	REST API	resources, HTTP methods, status codes, validation, CRUD
Lesson 06	File-based Database	JSON persistence, read/write helpers, .env, pagination

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Study Method

1. Read the lesson, then run the example with node.
2. Change one thing and observe what breaks — that is where the learning is.
3. Attempt the assignment before opening the reference solution.
4. Test every endpoint with curl or an HTTP client.
5. Keep a notes.md of errors you hit and how you fixed them.

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Setup

node --version
npm --version
mkdir node-course && cd node-course
npm init -y

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References

• Node.js documentation
• Express guide
• npm documentation
• MDN — HTTP response status codes

Course Overview

Data outlives code. This course teaches how to store it properly: the relational model, SQL from first principles to joins and indexes, SQLite in Node, Prisma for typed database access, and MongoDB for document-shaped data — 6 lessons.

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Prerequisites

• Basic JavaScript and Node.js
• A terminal and a code editor
• SQLite CLI (optional but useful): sqlite3 --version

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Lesson List

Lesson	Title	Key Topics
Lesson 01	Database Concepts	tables, keys, relationships, RDBMS vs NoSQL, SQLite
Lesson 02	SQL Basics	CREATE TABLE, INSERT, SELECT, WHERE, UPDATE, DELETE
Lesson 03	Advanced SQL	JOIN, GROUP BY, HAVING, subqueries, indexes, transactions
Lesson 04	Node.js + SQLite	better-sqlite3, prepared statements, CRUD API
Lesson 05	Prisma ORM	schema.prisma, migrations, relations, Prisma Client
Lesson 06	MongoDB Basics	documents, collections, Mongoose, Atlas, indexes

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Study Method

1. Write every query by hand before wrapping it in JavaScript.
2. Keep schema.sql in the project and rebuild the database from it.
3. Break things on purpose: insert a duplicate, violate a foreign key, then read the error.
4. Run EXPLAIN QUERY PLAN on at least one query per lesson.
5. For the ORM lessons, inspect the generated SQL (prisma studio, query logging).

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Setup

npm install better-sqlite3
sqlite3 shop.db < schema.sql

npm install -D prisma
npm install @prisma/client
npx prisma init --datasource-provider sqlite

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References

• SQLite documentation
• PostgreSQL tutorial
• Prisma documentation
• Mongoose documentation
• MongoDB Atlas