build-your-own-x

# build-your-own-x USE FOR: - "build X from scratch / implement X yourself" - "how does Docker/Git/database/web server actually work" - "deep dive into how technology X is implemented" - "learning compilers / interpreters / OS / networking internals" - "implement neural network from scratch" - "write your own shell / regex engine / search engine" - "understand blockchain / BitTorrent internals" tags: [education, from-scratch, systems, compilers, OS, database, Docker, Git, neural-network, blockchain, web-server, shell, regex] kind: reference category: pro-code-architecture --- ## What Is Build-Your-Own-X? Curated repo of step-by-step tutorials for recreating popular technologies from scratch. > "What I cannot create, I do not understand." — Richard Feynman - Repo: https://github.com/codecrafters-io/build-your-own-x - 300+ tutorials · 30 categories · 20+ programming languages - Stars: 330,000+ (one of the most-starred repos on GitHub) --- ## Complete Category Reference | # | Category | What You Build | Languages | |---|----------|---------------|-----------| | 1 | **3D Renderer** | Ray tracer, rasterizer, path tracer | C, C++, Java, JS, Python, Rust | | 2 | **AI Model** | GPT, diffusion model, CLIP, NeRF | Python, C++ | | 3 | **Augmented Reality** | AR overlay, marker tracking | JS, Python | | 4 | **BitTorrent Client** | Peer-to-peer file sharing | Go, Haskell, JS, Python, Rust | | 5 | **Blockchain / Crypto** | Bitcoin-like chain, smart contracts | Go, Haskell, Java, JS, Python, Rust | | 6 | **Bot** | Chatbot, IRC bot, Slack bot | Go, Java, JS, Python | | 7 | **Command-Line Tool** | CLI parser, progress bar, formatter | Go, Python, Rust | | 8 | **Database** | SQL engine, key-value store, Redis clone | C, C++, Go, Java, Python, Rust | | 9 | **Docker** | Container runtime, image builder | Go, Python | | 10 | **Emulator / VM** | CHIP-8, NES, Game Boy emulator | C, C++, Go, Java, JS, Rust | | 11 | **Frontend Framework** | React-like library, virtual DOM, JSX | JS, TS | | 12 | **Game** | Tetris, chess, Minecraft clone | C, C++, Go, Java, JS, Python | | 13 | **Git** | Version control from scratch | Go, Python, Haskell, Ruby | | 14 | **Memory Allocator** | malloc/free implementation | C | | 15 | **Network Stack** | TCP/IP stack, HTTP client | C, Go, Python | | 16 | **Neural Network** | Backprop from scratch, CNN, RNN | C, C++, Java, JS, Python | | 17 | **Operating System** | Bootloader, kernel, process scheduler | C, Rust | | 18 | **Physics Engine** | Rigid body, collision detection | C++, JS | | 19 | **Processor** | RISC-V CPU in HDL or emulation | C, Python | | 20 | **Programming Language** | Interpreter, compiler, VM, LISP | C, Go, Haskell, Java, JS, Python, Rust | | 21 | **Regex Engine** | NFA/DFA regex from scratch | C, Go, Java, JS, Python | | 22 | **Search Engine** | Inverted index, TF-IDF, BM25 | Python, Ruby | | 23 | **Shell** | Bash-like shell, job control | C, Go, Python, Rust | | 24 | **Template Engine** | Jinja/Mustache-like | JS, Python | | 25 | **Text Editor** | Vim-like, kilo editor | C | | 26 | **Visual Recognition** | MNIST classifier, face detection | Python | | 27 | **Voxel Engine** | Minecraft-style 3D world | C++ | | 28 | **Web Browser** | HTML parser, CSS layout, DOM | Python, Haskell | | 29 | **Web Server** | HTTP/1.1, static file server | C, Go, Java, Python, Rust | | 30 | **Distributed Systems** | Kafka-like, Raft consensus, MapReduce | Go, Java, Python | --- ## Quick Lookup: "Build Your Own X" by Language ### Python - Neural network (numpy only), web server, shell, regex engine, search engine, blockchain, BitTorrent, Docker, browser, Git, database (Redis/SQLite clone) ### Go - Docker, Git, BitTorrent client, web server, shell, database, distributed systems (Raft/Kafka) ### Rust - OS kernel, web server, shell, regex engine, database, 3D renderer, BitTorrent ### C / C++ - OS, memory allocator, text editor (kilo), 3D renderer, shell, neural network, database ### JavaScript / TypeScript - Frontend framework (React clone), game, bot, blockchain, web server, template engine ### Java - Blockchain, compiler, neural network, distributed systems --- ## Learning Path Recommendations ### Systems Programming Track ``` 1. Memory Allocator (C) → understand heap 2. Shell (C/Go/Rust) → processes, I/O, signals 3. Network Stack (C/Go) → TCP/IP fundamentals 4. Web Server (Go/Rust) → HTTP, concurrency 5. Operating System (C/Rust) → kernel, scheduling ``` ### Compiler / Language Track ``` 1. Regex Engine → NFA/DFA automata 2. Template Engine → parsing basics 3. Interpreter (LISP/calc) → AST, evaluation 4. Full Language (Python/Rust) → lexer → parser → codegen ``` ### AI / ML Track ``` 1. Neural Network (numpy/C) → backprop from scratch 2. Visual Recognition (MNIST) → CNN pipeline 3. AI Model (GPT-like) → transformer architecture 4. Diffusion Model → score-based generation ``` ### Distributed Systems Track ``` 1. BitTorrent Client → P2P, DHT 2. Blockchain → consensus, hashing 3. Kafka-like queue → log-structured storage 4. Raft consensus → leader election 5. MapReduce → distributed computation ``` ### Database Track ``` 1. Key-value store (Redis clone) → in-memory, persistence 2. SQL engine → parsing, query planning 3. B-tree storage engine → disk I/O, indexing 4. Full RDBMS → joins, transactions, ACID ``` --- ## CodeCrafters Integration Many guides are also available as interactive challenges at **codecrafters.io**: - Build Redis, Git, Docker, HTTP server, SQLite, Kafka, BitTorrent - Get automated test feedback as you build - Supported languages: Go, Python, Rust, Java, C, C++, and more --- ## Using This as a Skill Reference When a user asks "how does X work?" or "implement X from scratch": 1. Find X in the category table above 2. Route to the tutorial in preferred language 3. Use the learning path recommendations for sequencing 4. CodeCrafters for interactive guided versions ---