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.
Backend · Advanced · 2–3 weeks
Distributed Background Job Queue
A Redis-backed job system with multiple workers, retries, scheduled jobs, and a dead-letter queue, plus a small dashboard showing what's running and what failed.
- Go
- Redis
- PostgreSQL
- Docker Compose
- Prometheus
Features
- Enqueue API with priorities and delayed jobs
- Exponential-backoff retries and a dead-letter queue
- Horizontally scalable workers with graceful shutdown
- Idempotency keys that prevent duplicate processing
- Metrics endpoint for throughput, latency, and failure rate
Bonus: A chaos test script that kills workers mid-job and proves, with logs, that no job is ever lost.
Backend · Intermediate · 1–2 weeks
Webhook Relay & Replay Service
Receives webhooks from services like Stripe or GitHub, verifies their signatures, stores them, and forwards them reliably to your apps with retries and one-click replay.
- Node.js
- TypeScript
- Fastify
- PostgreSQL
- BullMQ
- OpenAPI
Features
- Per-source HMAC signature verification
- Durable storage with a searchable delivery log
- Retries with backoff and a per-endpoint circuit breaker
- Replay any stored event to any endpoint
- OpenAPI spec with generated API docs
Bonus: A small CLI that tunnels live events to localhost so developers can test webhooks on their own machine.
Backend · Advanced · 2 weeks
API Gateway with Rate Limiting
A reverse proxy that sits in front of your services and handles authentication, rate limiting, caching, and request logging so the services don't have to.
Features
- Config-driven routing to multiple upstream services
- Token-bucket rate limiting per API key, shared across instances through Redis
- JWT validation and API key management
- Response caching with TTLs and manual invalidation
- Structured access logs and latency metrics
Bonus: k6 load tests that publish p50, p95, and p99 latency with and without the gateway in front.
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.
Embedded & IoT · Intermediate · 1–2 weeks
ESP32 Air Quality Station
A connected sensor node that measures CO₂, PM2.5, temperature, and humidity, and streams readings over MQTT to a live dashboard.
- ESP32
- C++ (ESP-IDF or PlatformIO)
- MQTT
- InfluxDB
- Grafana
Features
- Sensor drivers over I²C and UART with calibration
- Deep-sleep power management for battery use
- MQTT with reconnect and local buffering during outages
- Over-the-air firmware updates
- Dashboard with thresholds and alerts
Bonus: A custom PCB designed in KiCad and a 3D-printed enclosure, shown in photos in the README.
Embedded & IoT · Advanced · 2–3 weeks
PID Motor Controller on FreeRTOS
A closed-loop DC motor speed and position controller on an STM32, with a desktop app for live plotting and tuning.
- STM32
- C
- FreeRTOS
- Quadrature encoder
- Python (PyQt, pyqtgraph)
Features
- Encoder reading using hardware timer peripherals
- PID loop running at a fixed rate in its own RTOS task
- Serial protocol with framing and checksums
- Desktop GUI with live plots and gain sliders
- Host-side unit tests for the control logic
Bonus: An auto-tuning routine (relay or Ziegler–Nichols) with a before/after step-response plot.
Embedded & IoT · Advanced · 2–3 weeks
FPGA Game Console with VGA Output
Pong or Breakout built entirely in hardware with Verilog, driving a VGA monitor straight from an FPGA board with no CPU at all.
- Verilog or SystemVerilog
- Vivado or Quartus
- Basys 3 or DE10-Lite board
- Verilator
Features
- VGA timing generator for 640×480 at 60 Hz
- Sprite drawing and collision logic in hardware
- Debounced button input and a score on the seven-segment display
- Testbenches with automated waveform checks
- Clean module hierarchy with resource and timing reports
Bonus: Sound effects generated in hardware through PWM audio output.
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.