Frontend · Intermediate · 2 weeks
Accessible Design System & Component Library
A themeable library of accessible UI components (dialog, combobox, tabs, data table, toast) published to npm, with a documentation site where people can try every component live.
- React
- TypeScript
- Storybook
- Vitest
- Testing Library
- axe-core
Features
- 8–10 components with full keyboard support and correct ARIA roles
- Light and dark theming driven by design tokens
- Docs site with a live props playground for each component
- Automated accessibility tests that run in CI on every pull request
- Versioned releases to npm with a generated changelog
Bonus: Visual regression testing with Playwright screenshots that block a PR if any component changes unexpectedly.
Frontend · Intermediate · 1–2 weeks
Git Repo Time-Lapse Visualizer
Paste any public GitHub repository and watch its file tree grow over time as an animated treemap, with contributor activity and the files that change most often.
- TypeScript
- Vite
- D3.js
- GitHub REST API
- Web Workers
Features
- Fetch and cache commit history with pagination and rate-limit handling
- Animated treemap playback with a timeline scrubber
- Contributor timeline and a churn heatmap of hot-spot files
- Heavy parsing moved into a Web Worker to keep animation smooth
- Shareable URLs that encode the repo and timestamp
Bonus: Export the playback as a WebM or GIF that people can drop straight into their own README.
Frontend · Intermediate · 2 weeks
Browser Logic Circuit Simulator
Drag gates, wires, clocks, and LEDs onto a canvas and watch signals propagate in real time. Build anything from a half adder to a tiny CPU in the browser.
- TypeScript
- Canvas 2D or SVG
- Vite
- Web Workers
- Vitest
Features
- Drag-and-drop gates, switches, clocks, LEDs, and seven-segment displays
- Event-driven simulation with propagation delay
- Truth-table generator for any selected circuit
- Reusable custom components built from sub-circuits
- Save, load, and share circuits by link
Bonus: A waveform timing-diagram viewer that works like a logic analyzer for any wire you probe.
Data & ML · Intermediate · 1–2 weeks
Resume ↔ Job Description Matcher
Upload a resume and a job posting. It scores how well they match, highlights missing skills, and suggests stronger bullet points.
- Python
- sentence-transformers
- spaCy
- FastAPI
- Streamlit
Features
- PDF parsing and section extraction (experience, skills, education)
- Skill extraction against a curated skills taxonomy
- Semantic similarity scoring with a readable explanation
- Gap report listing missing and weak skills
- A small labeled test set that measures accuracy
Bonus: Benchmark three embedding models on your test set and publish the results table in the README.
Data & ML · Intermediate · 1–2 weeks
Webcam Hand-Gesture Controller
Recognizes hand gestures from a webcam in real time and uses them to control slides, media playback, or smart lights.
- Python
- MediaPipe
- PyTorch or scikit-learn
- OpenCV
Features
- Hand landmark extraction from live video
- Data-collection tool for recording custom gestures
- Trained classifier with a confusion matrix and accuracy report
- Smoothing and debounce so actions don't misfire
- Config file that maps gestures to actions
Bonus: Export the model to ONNX and run it fully in the browser with a live demo page.
Data & ML · Advanced · 2–3 weeks
Predictive Maintenance for Jet Engines
Predicts the remaining useful life of jet engines from sensor time series using NASA's C-MAPSS dataset, served behind an API with a monitoring dashboard.
- Python
- pandas
- LightGBM or PyTorch
- MLflow
- FastAPI
- Docker
Features
- Exploratory analysis and time-series feature engineering
- A baseline model and an LSTM, compared with proper time-based validation
- Experiment tracking in MLflow
- Model served through FastAPI inside Docker
- Dashboard showing predictions per engine
Bonus: Data-drift detection that flags when incoming sensor data stops looking like the training data.
Data & ML · Intermediate · 2 weeks
Codebase Q&A Assistant
Index any Git repository and ask questions like "where is authentication handled?" Answers cite the exact files and lines they came from.
- Python
- tree-sitter
- sentence-transformers
- pgvector or Qdrant
- FastAPI
- An LLM API
Features
- Code-aware chunking by function and class using tree-sitter
- Hybrid keyword and vector search
- Answers with file and line citations
- Incremental re-indexing when new commits land
- An evaluation set of 30+ questions that measures retrieval accuracy
Bonus: A VS Code extension so you can ask questions without leaving the editor.
Systems · Advanced · 2–3 weeks
LSM-Tree Key-Value Store
A persistent key-value database built from scratch with a write-ahead log, memtable, SSTables, and compaction, like a tiny RocksDB.
- Rust or C++
- TCP
- criterion / Google Benchmark
Features
- Write-ahead log with crash recovery
- Memtable flushed to sorted SSTable files
- Bloom filters to skip unnecessary disk reads
- Background compaction
- Simple TCP protocol with a CLI client
Bonus: Benchmarks against SQLite with throughput and latency graphs in the README.
Systems · Advanced · 2–3 weeks
RISC-V Emulator with Debugger
An RV32I CPU emulator that runs real programs compiled with GCC, plus a step debugger for registers and memory.
- C++ or Rust
- RISC-V GCC toolchain
- SDL2 (optional)
Features
- Fetch, decode, and execute for the full RV32I instruction set
- ELF loader for compiled binaries
- Memory-mapped UART so programs can print
- Step debugger with register and memory views
- Passes the official riscv-tests suite
Bonus: A 5-stage pipeline view that visualizes hazards, stalls, and forwarding cycle by cycle.
Systems · Advanced · 2–3 weeks
Mini Container Runtime
Your own version of docker run, built from scratch: isolated processes with their own filesystem, process tree, network, and resource limits.
- Go or C
- Linux namespaces
- cgroups v2
- OverlayFS
Features
- PID, mount, UTS, and network namespaces
- Root filesystem set up with pivot_root from an image tarball
- CPU and memory limits using cgroups v2
- Layered filesystems with OverlayFS
- veth networking so containers can reach the internet
Bonus: Pull and run real images from Docker Hub by implementing the registry API.
Systems · Advanced · 2–3 weeks
Compiler for a Small Language
A compiler for your own small language, with variables, functions, loops, and structs, that outputs WebAssembly or x86-64 assembly and runs real programs.
- Rust, C++, or OCaml
- WebAssembly (WAT) or x86-64
- A test harness
Features
- Hand-written lexer and recursive-descent parser
- Type checker with clear error messages that point at the source
- An intermediate representation with constant folding and dead-code elimination
- Code generation to WebAssembly or assembly
- Test suite of example programs with expected output
Bonus: A web playground that compiles and runs programs right in the browser.
Security · Intermediate · 1–2 weeks
Git Secrets Scanner & GitHub Action
A CLI and GitHub Action that scans repositories, including full commit history, for leaked API keys, passwords, and private keys.
- Go
- Regex + entropy analysis
- GitHub Actions
- SARIF
Features
- Pattern and entropy-based secret detection
- Fast scanning of the full Git history
- Allowlist file to suppress false positives
- SARIF output that shows up in GitHub code scanning
- Pre-commit hook mode that blocks leaks before they happen
Bonus: A seeded test corpus that reports precision and recall, compared against an existing open-source scanner.
Security · Intermediate · 1–2 weeks
SSH Honeypot with Attack Dashboard
A fake SSH server on a cheap cloud VM that records the logins and commands real attackers try, shown on a live dashboard.
- Python (asyncssh) or Go
- Docker
- PostgreSQL
- Grafana
- GeoLite2
Features
- Fake shell that imitates a Linux machine and logs every command
- Analytics on the most common passwords and commands
- World map of where attempts come from
- Strong isolation: its own VM, a container, and no outbound network
- Automatically generated weekly threat summary
Bonus: A write-up analyzing one week of real attack data, published alongside the repo.
Security · Advanced · 2 weeks
End-to-End Encrypted File Sharing
Share files by link, with encryption done in the browser so the server never sees file contents or keys.
- TypeScript
- Web Crypto API
- Node.js or Go
- S3-compatible storage
Features
- AES-GCM encryption in the browser, with the key kept only in the URL fragment
- Chunked streaming encryption for large files
- Links that expire or stop after a set number of downloads
- Optional password protection with proper key derivation
- A written threat model in the README
Bonus: A verification page that shows the stored ciphertext is unreadable without the link.
Games · Advanced · 2–3 weeks
Multiplayer Arena with Real Netcode
A fast top-down browser arena game with an authoritative server, client-side prediction, and lag compensation, so it feels smooth even at 150 ms ping.
- TypeScript
- HTML Canvas or Phaser
- Node.js
- WebSockets
Features
- Authoritative server running at a fixed tick rate
- Client-side prediction with server reconciliation
- Entity interpolation for other players
- Lobby and simple matchmaking
- Built-in network simulator with latency and packet-loss sliders
Bonus: A replay system that records inputs and plays back any match deterministically.
Games · Intermediate · 2–3 weeks
Procedural Roguelike with ECS
A turn-based dungeon crawler with procedurally generated levels, built on an entity-component-system architecture.
- Rust + Bevy
- or C# + Godot
- WebAssembly build
Features
- Seeded dungeon generation using BSP or cellular automata
- Entity-component-system architecture for all game objects
- Field of view and A* pathfinding for enemies
- Items, inventory, and save/load
- A playable web build published on itch.io
Bonus: A daily seeded challenge where everyone plays the same dungeon.