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.
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.