Battle Arena
Choose your challenge and prove your prompting skills
Showing 29 battles
Bytecode Virtual Machine
Build a stack-based bytecode VM with instruction set, execution engine, and simple compiler.
B-Tree Index
Implement a B-tree data structure with disk-based persistence suitable for database indexing.
WebSocket Server
Build a WebSocket server from raw TCP with handshake, framing, and pub/sub rooms.
JSON Database
Build a document-oriented database engine that stores JSON documents with querying and indexing.
Template Engine
Build a template engine with variable interpolation, control flow, partials, and inheritance.
Shell Interpreter
Build a Unix-like shell with pipes, redirection, job control, and scripting.
Diff Algorithm
Implement Myers diff algorithm with unified diff output and semantic cleanup.
Pub/Sub Message Broker
Build a publish/subscribe message broker with topics, consumer groups, and persistence.
Schema Validator
Build a JSON Schema validator supporting draft-07 with detailed error reporting.
DNS Resolver
Build a recursive DNS resolver that queries root servers and caches results.
Git Internals
Implement git's core object model — blob, tree, commit storage with refs and basic commands.
Code Linter
Build a pluggable JavaScript/TypeScript linter with AST analysis and auto-fixing.
Package Manager
Build a package manager with dependency resolution, lockfile, and registry client.
CSS Selector Engine
Build a CSS selector matching engine that queries a DOM tree.
Event Sourcing Engine
Build an event sourcing system with event store, projections, and snapshots.
Rate Limiter Service
Build a distributed-ready rate limiter with multiple algorithms and HTTP middleware.
Markdown to PDF Renderer
Build a Markdown-to-PDF converter with custom styling, page layout, and table of contents.
GraphQL Server
Build a GraphQL server with schema parsing, query execution, and subscriptions.
Terminal Text Editor
Build a terminal-based text editor with syntax highlighting, search, and multiple buffers.
Container Runtime
Build a minimal container runtime using Linux namespaces and cgroups.
In-Memory File System
Build a POSIX-like in-memory file system with directories, permissions, and hard/soft links.
Protocol Buffer Serializer
Build a Protocol Buffers serializer/deserializer with schema compilation.
Cron Scheduler
Build a cron daemon that parses cron expressions and executes scheduled jobs.
Blockchain
Build a basic blockchain with proof-of-work mining, transactions, and P2P networking.
Ray Tracer
Build a ray tracer that renders 3D scenes with lighting, reflections, and shadows.
Distributed Hash Table
Build a Kademlia-style DHT for decentralized key-value storage.
Spreadsheet Engine
Build a spreadsheet engine with formula evaluation, cell references, dependency graphs, and cycle detection.
Tiny Language Compiler
Build a compiler for a small language: lexer, parser, AST, and code generation targeting JavaScript or bytecode.
HTTP Server From Scratch
Build an HTTP/1.1 server using only TCP sockets — parse requests, route handlers, serve static files, and support keep-alive.