My work

Portfolio

Five projects I built entirely myself - from architecture to deployment, on my own servers, with my own backend.

LiveAndroidKotlin

GrowTracker Android App

Native grow management for Android

growtracker.de →

Native Android app for plant management, tasks, statistics, DLI calculator and BLE sensors - with JWT auth and 2FA.

Features

  • Plant management with profiles & photos
  • Task system with reminders
  • Growth statistics & charts
  • DLI, fertilizer and nutrient calculators
  • BLE sensor integration
  • JWT authentication + 2FA (TOTP)
  • Offline-capable core features

Tech Stack

FrontendAndroid (Kotlin)
BackendNode.js, Express
DatabaseMySQL
AuthJWT + 2FA (TOTP)
ServerLinux, nginx, systemd
HostingOwn VPS
LiveCMSNode.js

GrowTracker CSC Management

Cannabis Social Club administration

cms.growtracker.de →

Management system for Cannabis Social Clubs: members, inventory, partner directory, push messages and admin dashboard.

Features

  • Member management & roles
  • Inventory and distribution management
  • Partner directory with map
  • Push messages to members
  • Statistics & admin dashboard
  • Application workflow for new clubs
  • Audit log & secure admin auth

Tech Stack

FrontendVanilla JS, HTML/CSS
BackendNode.js, Express
DatabaseMySQL
AuthJWT + CSRF
ServerLinux, nginx, PM2
Hostingcms.growtracker.de
LivePWAVanilla JS

GrowTracker Web App

Progressive Web App

Open web app →

Full PWA with plant management, calculators, community forum and synced backend - runs on all devices.

Features

  • Plant management & tasks
  • DLI, fertilizer and nutrient calculators
  • Community forum
  • PWA - installable on all devices
  • Responsive for desktop & mobile
  • Synchronized with backend API

Tech Stack

FrontendVanilla JS, PWA
BackendNode.js, Express
DatabaseMySQL
AuthJWT + 2FA (TOTP)
ServerLinux, nginx
URLgrowtracker.de/webapp
BetaFastAPINext.js

StickGuard

Hardware security system

Learn more →

Hardware security system with web dashboard, desktop agent and policy engine - ECDSA auth, audit logging and live WebSocket updates.

Features

  • ECDSA challenge-response authentication
  • Policy engine (block_all, block_device)
  • Audit logging & live WebSocket updates
  • RBAC with superadmin, admin and user
  • Multi-tenant with tenant switching
  • CRUD for devices, policies, users and tenants

Tech Stack

FrontendNext.js
BackendFastAPI, Python
DatabaseSQLite
AgentPython desktop agent
AuthECDSA + RBAC
DeployDocker, Nginx
BetaAndroidKotlin

NookDay

Stress-free Android day planner

Discover app →

Modern habit and day planner without streaks or pressure. Habits, appointments and shopping list in one calm Android app.

Features

  • Habits without streaks or pressure
  • Day planner with week view & appointments
  • Shopping list sorted by category
  • Built-in step counter & statistics
  • Local storage & full privacy
  • Optional Firebase AI (Gemini) integration

Tech Stack

FrontendAndroid (Kotlin)
UIJetpack Compose
DatabaseRoom (SQLite)
ArchitectureMVVM + StateFlow
AlarmsAlarmManager
DeployGoogle Play Store
Get in touch

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