gaku52/04-web-and-network/backend-development

Backend Development — Complete Guide

A comprehensive guide to backend engineering. Covers the fundamentals of HTTP, REST API design, databases, authentication, environment configuration, and algorithm proofs — everything needed to build robust server-side systems.

Target Audience

• Developers new to backend engineering
• Frontend engineers expanding toward full-stack development
• Engineers looking to solidify their understanding of server-side fundamentals

Prerequisites

• Basic programming knowledge (variables, functions, control flow)
• Familiarity with the command line

Guide Index

01-basics (Fundamentals)

| File | Topic | Overview | |------|-------|----------| | 01-what-is-backend.md | What Is Backend | Roles, responsibilities, and the frontend/backend boundary | | 02-http-basics.md | HTTP Basics | Methods, status codes, requests, and responses | | 03-rest-api-intro.md | REST API Intro | REST principles, resource design, endpoint patterns | | 04-database-intro.md | Database Intro | SQL basics, ORM, and table design | | 05-authentication-basics.md | Authentication Basics | Auth vs. authz, JWT, password hashing | | 06-environment-variables.md | Environment Variables | .env files, python-dotenv, Pydantic Settings | | 07-simple-api-tutorial.md | Simple API Tutorial | End-to-end task management API with FastAPI |

02-api-design (API Design)

| File | Topic | Overview | |------|-------|----------| | api-design-complete.md | API Design Complete | REST, GraphQL, gRPC, versioning, rate limiting, docs |

03-error-handling (Error Handling)

| File | Topic | Overview | |------|-------|----------| | error-handling-complete.md | Error Handling Complete | Structured error responses, global handlers, logging |

04-security (Security)

| File | Topic | Overview | |------|-------|----------| | security-complete.md | Security Complete | OWASP Top 10, input validation, HTTPS, secrets management |

05-algorithms (Algorithm Proofs)

| File | Topic | |------|-------| | sorting-algorithms-proof.md | Sorting Algorithms | | binary-search-proof.md | Binary Search | | hash-table-proof.md | Hash Table | | graph-traversal-proof.md | Graph Traversal | | dynamic-programming-proof.md | Dynamic Programming | | avl-tree-proof.md | AVL Tree | | red-black-tree-proof.md | Red-Black Tree | | dijkstra-algorithm-proof.md | Dijkstra's Algorithm | | astar-pathfinding-proof.md | A* Pathfinding | | minimum-spanning-tree-proof.md | Minimum Spanning Tree | | network-flow-proof.md | Network Flow | | topological-sort-proof.md | Topological Sort | | union-find-proof.md | Union-Find | | segment-tree-proof.md | Segment Tree | | fenwick-tree-proof.md | Fenwick Tree | | skip-list-proof.md | Skip List | | bloom-filter-proof.md | Bloom Filter | | trie-proof.md | Trie | | fft-proof.md | Fast Fourier Transform | | convex-hull-proof.md | Convex Hull | | strassen-matrix-multiplication-proof.md | Strassen Matrix Multiplication | | string-matching-proof.md | String Matching |

Learning Path

Fundamentals:    01-basics (01 → 07 in order)
API Design:      02-api-design
Error Handling:  03-error-handling
Security:        04-security
Algorithms:      05-algorithms (reference as needed)

FAQ

Q1: Which programming language should I use for the backend?

The examples in this guide primarily use Python (FastAPI) because it is beginner-friendly and widely used in data-intensive applications. However, the concepts — HTTP, REST, databases, authentication — apply universally. Choose based on your team's skills, project requirements, and ecosystem. Node.js/TypeScript is an excellent alternative, especially when you want to share code between frontend and backend.

Q2: Do I need to learn SQL even if I plan to use an ORM?

Yes. ORMs simplify day-to-day operations, but understanding the SQL they generate is critical for debugging slow queries, reasoning about indexes, and designing schemas. A solid SQL foundation will make you a better ORM user.

Q3: How important is security from the start?

Security is not an add-on — it must be considered from the initial design. The guide covers the most impactful practices: hashing passwords, using JWT correctly, validating all input, and keeping secrets out of version control. Follow these from day one rather than retrofitting them later.

Summary

This guide covers:

• The role of the backend and how it differs from the frontend
• HTTP fundamentals, REST API design principles, and endpoint naming conventions
• Relational databases, SQL basics, ORM usage, and schema design
• Authentication (JWT) and authorization patterns with secure password storage
• Environment variable management for multiple deployment environments
• Advanced API design covering REST, GraphQL, and gRPC
• Error handling strategies and security best practices
• Mathematical proofs for 22 fundamental algorithms and data structures

References

1. Fielding, Roy. "Architectural Styles and the Design of Network-based Software Architectures." UC Irvine, 2000.
2. FastAPI. "FastAPI Documentation." fastapi.tiangolo.com, 2024.
3. SQLAlchemy. "SQLAlchemy Documentation." sqlalchemy.org, 2024.
4. OWASP. "OWASP Top Ten." owasp.org, 2024.
5. Cormen, T. et al. "Introduction to Algorithms." MIT Press, 2022.

Related Skills

• Node.js Development — Node.js and Express/NestJS
• Web Application Development — Frontend frameworks and deployment
• Network Fundamentals — TCP/IP, DNS, and HTTP deep dive