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
- Shapes, freehand drawing, and sticky notes
- Live cursors and presence indicators
- Conflict-free merging of simultaneous edits using CRDTs
- Shareable boards with view-only and edit links
- 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
- Shared editor with synced cursors and selections
- Run Python, JavaScript, or C++ in isolated containers with CPU, memory, and time limits
- Private notes panel only the interviewer can see
- Session playback of the whole interview
- 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
- HTTP, TCP, and keyword checks run on a schedule by a worker
- Incident detection that confirms with retries to avoid false alarms
- 90-day uptime bars and response-time charts
- Email and Discord alerts when something goes down
- Admin page for posting incident updates
Bonus: Checks from two regions that only open an incident when both agree the service is down.
DevOps & Cloud · Advanced · 2–3 weeks
GitOps Kubernetes Home Lab
A fully automated Kubernetes cluster where pushing to Git builds, scans, and deploys your apps, with monitoring and alerts built in.
- Terraform
- k3s
- Argo CD
- Helm
- Prometheus
- Grafana
- GitHub Actions
Features
- Infrastructure as code for all VMs or cloud instances
- CI pipeline that builds, scans, and pushes container images
- Argo CD auto-sync from a Git repository
- Grafana dashboards and alert rules
- Secrets managed safely with Sealed Secrets
Bonus: Canary rollouts that roll back automatically when the error rate spikes.
DevOps & Cloud · Intermediate · 1–2 weeks
Distributed Tracing Playground
Three small microservices instrumented end to end, so you can follow a single request across every service with linked logs, metrics, and traces.
- OpenTelemetry
- Docker Compose
- Jaeger or Tempo
- Prometheus
- Grafana
- Loki
Features
- Three services in two languages, instrumented with OpenTelemetry
- Trace context carried through HTTP calls and a message queue
- Dashboards for rate, errors, and duration
- Logs linked to their trace IDs
- SLOs with burn-rate alerts
Bonus: A fault-injection switch that adds latency or errors so viewers can see exactly how problems show up.
DevOps & Cloud · Intermediate · 1–2 weeks
Serverless Media Pipeline on AWS
Upload an image or video and an event-driven pipeline resizes, transcodes, and tags it automatically. All infrastructure is defined in code.
- AWS S3, Lambda, SQS, DynamoDB
- AWS CDK or Terraform
- TypeScript or Python
- GitHub Actions
Features
- Direct uploads using presigned URLs
- S3 events feeding SQS and Lambda, with retries and a dead-letter queue
- Thumbnails and metadata stored in DynamoDB
- Least-privilege IAM roles for every function
- CI/CD that deploys separate dev and prod stages on merge
Bonus: A cost report in the README showing the real cost per 1,000 uploads.
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.
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.