Foundation 100

- HTTP
- REST APIs
- Authentication
- JWT Authentication
- Authorization
- Password Hashing
- CRUD Operations
- Request Validation
- Error Handling
- Environment Variables
- Relational Databases
- PostgreSQL
- SQL Fundamentals
- Database Tables
- Primary Keys
- Foreign Keys
- Database Relationships
- Prisma ORM
- Prisma Migrations
- Prisma Client
- Unit Testing
- Jest
- Mocking
- Integration Testing
- End-to-End Testing
- Test Coverage
- Linting
- Static Analysis
- Debugging
- Code Reviews
- Git Basics
- Branching
- Merge
- Rebase
- Conflict Resolution
- Semantic Commits
- Pull Requests
- GitHub Workflow
- Code Ownership
- Release Versioning
- Docker
- Docker Compose
- Build Pipelines
- CI/CD
- Environment Configuration
- Secrets Management
- Reverse Proxy
- Deployment Strategies
- Monitoring
- Centralized Logging
- SOLID Principles
- Design Patterns
- Layered Architecture
- Clean Architecture
- Domain Modeling
- System Design Basics
- Scalability
- Performance
- Security Principles
- Technical Debt

Engineering foundations, explained clearly.

The knowledge behind Padlor — a structured, practical path through the concepts real engineers use every day, from HTTP to architecture.

It is an expanding library. We publish the full outline so you can see where it is going, and write it module by module — 57 topics are readable now, and the rest are marked as planned. Everything published is finished writing; nothing here is a stub.

Start with the Foundation 100 Browse by technology →

The Foundation 100

The full outline, ten modules deep. Each card shows how much of that module is written and ready to read.

All modules →

Module 15/10 written

Web Fundamentals

How the web works — HTTP, REST, authentication, and the core request and response building blocks every backend shares.

Module 29/10 written

Node.js & Express Foundations

Running JavaScript on the server and building HTTP APIs with Node.js and Express.

Module 30/10 written

Database & Prisma Foundations

Relational data modelling with PostgreSQL and type-safe access through Prisma.

Module 410/10 written

API Design & Backend Patterns

Designing clean, evolvable APIs — DTOs, pagination, versioning, and the patterns behind them.

Module 510/10 written

React Foundations

Building user interfaces with components, props, state, and the core mechanics of React.

Module 610/10 written

Frontend Architecture

Structuring real React applications — routing, state management, data fetching, and performance.

Module 70/10 written

Testing & Quality

Testing strategy and code quality — from unit tests to end-to-end, plus linting and reviews.

Module 80/10 written

Git & Collaboration

Version control and team workflow — branching, merging, pull requests, and releases.

Module 90/10 written

DevOps & Deployment

Shipping software — containers, pipelines, configuration, and safe deployment.

Module 109/10 written

Software Engineering & Architecture

Principles and patterns for designing systems that scale and endure.

Explore by technology

All technologies →

Node.js30 React20 Express9 NestJS8 REST API7 TypeScript7 JavaScript6 HTTP5 Authentication2 CSS2

Recently added

beginner12 min read

Media Queries

A way to apply CSS rules only when a condition about the display holds — most often a minimum width — so a layout can change as the space available changes.

beginner13 min read

CSS Styling and Properties

Learn how CSS controls the appearance of HTML elements, how CSS rules are written, and how common properties are used to style text, colors, spacing, sizing, borders, backgrounds, layouts, and interactive states.

beginner11 min read

Deploying a Web Project to Netlify

Building a web project on your computer is only the beginning. Deployment makes that project available on the internet so that other people can open it in a browser. In this topic, you will learn how to deploy a web project to Netlify and turn a project on your computer into a live website with a shareable web address. You will learn two common approaches: Manual deployment — upload your project directly to Netlify. GitHub deployment — connect a GitHub repository to Netlify so Netlify can deploy the project from your repository. You will also learn the basic ideas behind hosting, deployment, publish directories, build commands, deployment updates, and common beginner deployment problems. The examples can be applied to simple HTML/CSS/JavaScript projects such as calculators, games, and small websites, as well as other frontend projects that Netlify supports.

beginner10 min read

Publishing Your Project to GitHub

Git helps you track the history of your project on your computer. GitHub gives you a place to store that Git repository online, making your project easier to back up, share, and access from other computers. In this topic, you will learn how to create a GitHub repository, connect it to an existing local project, commit your changes, and publish those commits to GitHub. You will also learn the difference between Git and GitHub, understand what a remote repository is, and see how Git clients such as GitHub Desktop, VS Code, and the Git command line can be used to perform the same workflow. The examples use a small project such as a JavaScript calculator so you can see the complete journey from a project on your computer to a project stored on GitHub.

beginner2 min read

React Components

The building block of a React app: a function that returns markup describing a piece of the UI, which you compose together to build whole screens.

beginner2 min read

HTTP

How clients and servers communicate on the web through stateless request and response messages made of methods, paths, headers, and status codes.