Project Roulette / Projects

Backend, Full-stack, Mobile, Systems and Security projects

15 of 30 projects. Each has a stack, five features to ship, a difficulty, a time estimate, and a bonus challenge.

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

  1. Enqueue API with priorities and delayed jobs
  2. Exponential-backoff retries and a dead-letter queue
  3. Horizontally scalable workers with graceful shutdown
  4. Idempotency keys that prevent duplicate processing
  5. 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

  1. Per-source HMAC signature verification
  2. Durable storage with a searchable delivery log
  3. Retries with backoff and a per-endpoint circuit breaker
  4. Replay any stored event to any endpoint
  5. 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.

  • Go
  • Redis
  • JWT
  • Docker
  • k6

Features

  1. Config-driven routing to multiple upstream services
  2. Token-bucket rate limiting per API key, shared across instances through Redis
  3. JWT validation and API key management
  4. Response caching with TTLs and manual invalidation
  5. Structured access logs and latency metrics

Bonus: k6 load tests that publish p50, p95, and p99 latency with and without the gateway in front.

Full-stack · Advanced · 2–3 weeks

Real-time Collaborative Whiteboard

A multiplayer canvas where several people draw, add sticky notes, and see each other's cursors live, with edits that never conflict.

  • React
  • TypeScript
  • Yjs (CRDT)
  • WebSockets
  • Node.js
  • PostgreSQL

Features

  1. Shapes, freehand drawing, and sticky notes
  2. Live cursors and presence indicators
  3. Conflict-free merging of simultaneous edits using CRDTs
  4. Shareable boards with view-only and edit links
  5. Persistent boards with version history

Bonus: Offline editing that merges cleanly with everyone else's changes when you reconnect.

Full-stack · Advanced · 2–3 weeks

Live Coding Interview Room

Create a room, share a link, and code together in a shared editor. Code runs in sandboxed containers and both people see the output.

  • Next.js
  • Monaco Editor
  • WebSockets
  • Docker
  • Redis

Features

  1. Shared editor with synced cursors and selections
  2. Run Python, JavaScript, or C++ in isolated containers with CPU, memory, and time limits
  3. Private notes panel only the interviewer can see
  4. Session playback of the whole interview
  5. Rooms that expire and clean up automatically

Bonus: Hidden test cases that grade the candidate's solution automatically and show a pass/fail report.

Full-stack · Intermediate · 2 weeks

Uptime Monitor & Public Status Page

Monitors websites and APIs every minute, detects outages, opens incidents, and publishes a clean public status page with uptime history.

  • Next.js
  • TypeScript
  • PostgreSQL
  • Node.js worker
  • Email or Discord webhooks

Features

  1. HTTP, TCP, and keyword checks run on a schedule by a worker
  2. Incident detection that confirms with retries to avoid false alarms
  3. 90-day uptime bars and response-time charts
  4. Email and Discord alerts when something goes down
  5. Admin page for posting incident updates

Bonus: Checks from two regions that only open an incident when both agree the service is down.

Mobile · Intermediate · 2–3 weeks

Offline-first Field Inspection App

A mobile app for technicians who inspect equipment on site: checklists, photos, and signatures that work with no signal and sync later.

  • React Native (Expo)
  • TypeScript
  • SQLite
  • Supabase

Features

  1. Dynamic checklist templates loaded from the server
  2. Photo capture with on-image annotation
  3. Local-first storage with background sync and conflict handling
  4. Signature capture and PDF report export
  5. GPS-tagged inspections

Bonus: A small web admin dashboard where managers create templates and review submitted inspections.

Mobile · Intermediate · 2 weeks

Bluetooth LE Sensor Companion App

A phone app that discovers a Bluetooth Low Energy sensor, streams live readings, keeps a history, and sends settings back to the device.

  • Flutter (Dart)
  • flutter_blue_plus
  • SQLite
  • ESP32 or nRF52 as the peripheral

Features

  1. Scan, connect, and auto-reconnect to the device
  2. A custom GATT service and characteristics that you define
  3. Live charts of incoming readings
  4. Local history with CSV export
  5. Write settings like sample rate and thresholds back to the device

Bonus: Firmware updates delivered over Bluetooth straight from the app.

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

  1. Write-ahead log with crash recovery
  2. Memtable flushed to sorted SSTable files
  3. Bloom filters to skip unnecessary disk reads
  4. Background compaction
  5. 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

  1. Fetch, decode, and execute for the full RV32I instruction set
  2. ELF loader for compiled binaries
  3. Memory-mapped UART so programs can print
  4. Step debugger with register and memory views
  5. 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

  1. PID, mount, UTS, and network namespaces
  2. Root filesystem set up with pivot_root from an image tarball
  3. CPU and memory limits using cgroups v2
  4. Layered filesystems with OverlayFS
  5. 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

  1. Hand-written lexer and recursive-descent parser
  2. Type checker with clear error messages that point at the source
  3. An intermediate representation with constant folding and dead-code elimination
  4. Code generation to WebAssembly or assembly
  5. 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

  1. Pattern and entropy-based secret detection
  2. Fast scanning of the full Git history
  3. Allowlist file to suppress false positives
  4. SARIF output that shows up in GitHub code scanning
  5. 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

  1. Fake shell that imitates a Linux machine and logs every command
  2. Analytics on the most common passwords and commands
  3. World map of where attempts come from
  4. Strong isolation: its own VM, a container, and no outbound network
  5. 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

  1. AES-GCM encryption in the browser, with the key kept only in the URL fragment
  2. Chunked streaming encryption for large files
  3. Links that expire or stop after a set number of downloads
  4. Optional password protection with proper key derivation
  5. A written threat model in the README

Bonus: A verification page that shows the stored ciphertext is unreadable without the link.