deen
deen

As a senior full-stack developer I build and run web platforms, from large industrial projects to applications of my own.

  • I have worked in software development since 2012 and have built portals, product configurators, booking and shop systems, SaaS applications and developer tools, among other things.

  • My main tools are TypeScript, React, Next.js, Vue and Nuxt, Node.js, Go, Ruby on Rails, PHP and PostgreSQL. For operations I rely on Docker and Coolify.

  • In the team I clarify requirements in workshops, estimate effort, carry out code reviews and help new colleagues get started. Coding agents are a fixed part of how I work.

Career

  1. NYO GmbHsince 01/2026
  2. Pocket Rocket GmbH10/2025–12/2025
  3. Plan Software GmbH2018–09/2025
  4. Kern GmbH2014–2018
  5. Personal projectssince 2008
  6. Umwelt-Campus Birkenfeld2009–2016
  7. Gymnasium am Steinwald1998–2008

Professional career

  1. since 01/2026

    NYO GmbHSt. Wendel

    Architecture and technical ownership

    • Ownership of several products from specification to production: architecture, choice of technology, implementation, deployment and maintenance
    • Architecture of a product family: a shared sign-in service over OpenID Connect, sync between the applications via outbox and webhooks, multi-tenancy, background jobs
    • Migration strategy for a large existing system: the frontend is replaced step by step while it stays in use, instead of in one big switch
    • Operations concept for a production environment in a sovereign cloud (OpenStack): deployments through Coolify, administration only over VPN (WireGuard), intrusion detection with CrowdSec
    • Automated provisioning of customer instances from product templates, with separate, encrypted secrets per customer
    • Security as part of the work: documented security audits, encrypted credentials (AES-256-GCM), signed webhooks, open services moved behind login and rate limits
    • Quality and operations: tests with Vitest and Playwright, load tests with k6, observability with OpenTelemetry, CI/CD
    • Documentation that keeps up: specifications before building, API documentation with OpenAPI, architecture and deployment documents

    Development

    • Ticket and helpdesk system with kanban, sprints, Gantt, wiki, customer portal and an embeddable report widget, synced both ways with GitHub
    • Customer portal with central sign-in, appointment booking, company and tenant management, subscriptions and dunning
    • Telematics platform: devices from different manufacturers connected through configurable mappings, live map, geofence editor, alerts and reports on TimescaleDB and PostGIS
    • New frontend for a large existing system (Nuxt 4) with full-text search, two-factor sign-in, single sign-on and a mobile interface, plus work on the Rails API
    • AI in products: structured AI tasks with schema validation and model routing across several providers (Anthropic, OpenAI, Groq)
    • Website builder whose pages consist only of blocks with fixed schemas, so AI edits cannot break the structure
    • Tech stack: TypeScript, Next.js, React, Nuxt, Vue, Ruby on Rails, PostgreSQL with TimescaleDB and PostGIS, Drizzle ORM, Better Auth, BullMQ, Redis, Meilisearch, MapLibre, Turborepo, Docker, Coolify, Vitest, Playwright

  2. 10/2025–12/2025

    Pocket Rocket GmbHSt. Wendel

    Full-stack development

    • Lead developer of a SaaS for digital accessibility: an embeddable widget, a dashboard per website and a crawler that translates whole websites in advance into many languages or, with AI, into plain language
    • Single sign-on for a municipal platform through Keycloak (OAuth 2.0 with PKCE), alongside the existing login, with token exchange in the backend and documentation in sequence diagrams
    • Configurable import engine for events and news in a citizens' app: mapping, preview and schedule per source, maintained in the admin, covered by tests
    • Rebuilt search and map of a platform for social services: eight filters, and the map loads all locations with one filtered query instead of many single ones
    • Extensions to a smart city API in Ruby on Rails: short URLs, a file proxy, internal news and asynchronous mail delivery
    • Tech stack: TypeScript, Next.js, React, Nuxt, Vue, Prisma, PostgreSQL, Laravel, Filament, Ruby on Rails, Keycloak, Leaflet, Ionic, Capacitor, Tailwind CSS, Docker

  3. 2018–09/2025

    Plan Software GmbHSaarbrücken

    Senior full-stack developer in an industrial setting

    • Technical Lead, responsible for architecture, technical implementation, and team coordination
    • Developing full-stack web applications with a focus on UI/UX in the areas of e-commerce, configuration, and IoT

    Projects

    • Web product configurator for an industrial client: set up the monorepo and led its further development. Fitting in 2D with collision checks and magnetic snapping, a 3D view with three.js and a physics engine, dimension sheets, CAD export, prices from SAP, bills of materials and hand-over to the web shop
    • A module for terminal blocks with numbering and bridges, and a tool that checks CAD drawings (DXF) against dimension tables
    • B2B customer area with cart, multi-step checkout including SAP availability checks, a quotation process open to guests, order and quotation history, returns and live status over WebSocket, launched in 2022
    • Login theme for Keycloak (Keycloakify, React) with translations, debtor selection and guest enquiries
    • Spare parts web shop: redesign in the team, later individual features
    • Android and iOS app (React Native, AWS, push notifications)
    • Checking npm dependencies for compromised packages before every deployment in CI
    • Server administration (Apache, Nginx, Docker)

    Responsibilities in the team

    • Performing code reviews and other quality assurance activities
    • Requirements analysis and customer workshops
    • Requirement engineering support and effort estimates
    • Creation and implementation of design prototypes (Adobe Creative Suite)
    • Interview support (technical evaluation)
    • Onboarding and mentoring of teammates, technical contact for frontend topics
    • Tech stack: JavaScript, TypeScript, React, React Native, Redux Toolkit, TanStack Query, three.js, Konva, Node.js, Express, PHP, TYPO3, MSSQL, Keycloak, Turborepo, GitLab CI

  4. 2014–2018

    Kern GmbHBexbach

    Web shops/CMS (Joomla, WordPress, PrestaShop, Magento)

    • Extension development

    In-house developments

    • Web shop
    • Web2Print tool (online PDF creation)
    • Cloud (file manager)
    • User and job management
    • 3D developments
    • Invoice/inventory monitoring portal

    Other areas of activity

    • Supervision and training of students and trainees (business information systems and media design departments)
    • Media design, digital and print

  5. since 2008

    Personal projectsNeunkirchen

    Products and tools

    • plxr, a control room for coding CLIs such as Claude Code, Codex and Gemini: a Go service manages the terminals, the interface is built in Next.js and runs in a Wails window; four skins, installers for macOS, Linux and Windows
    • packbar, packing lists for trips: templates, categories with drag and drop, sharing by link to read or to edit, the weather at the destination and a last-minute reminder by email; built from a specification in two days
    • hauptsach-guddgess.de, a recipe portal with communities, cooking events, meal planning, cookbooks as PDF, moderation and recipe import from photos with AI
    • SLAB Display Builder: a web editor for the screens of an ESP32 touch display, flashing over WebSerial straight from the browser, and C++ firmware that interprets JSON layouts at runtime
    • Ariane, capacity planning for a development team: a weekly grid across twelve months, views by person and by project, spreadsheet-style input with undo, public holidays by region, Excel export
    • Tools for working with coding agents: a macOS overlay for running sessions (SwiftUI) and a monitor for usage limits (Python)

    Platforms and websites

    • Siriburi Thai Spa: a system of its own to replace WordPress and WooCommerce, with online booking including couple and group bookings and safe slot allocation, a voucher shop with PayPal and QR codes, back office and GDPR export and erasure
    • WaterSports Center Dénia: booking platform for water sports, restaurant, rentals and sun loungers with capacities, QR tickets, administration and six languages, built in three days
    • m8werk-pages: a headless CMS for five bilingual company websites, among them m8werk.de, and5.de and immosaar24.de. Translations, legal texts, files and maintenance mode are loaded at runtime through an API, one Dockerfile for all apps
    • FinHolding: FinForms, a portal for mortgage brokers with self-disclosure forms and a connection to the Europace APIs, sensitive fields encrypted. Plus the white-label enquiry app FinPhase with a form configurator per tenant and PDFs in the browser, and finholding.de and finforms.de in a monorepo with a new CI
    • Form builder based on a JSON tree, with an MCP server through which a local language model creates valid forms
    • Atrium: multi-tenant property platform with administration and public portal, roles and permissions, search with Meilisearch and self-hosted vector maps
    • My own infrastructure: Git hosting with Gitea and CI, deployments through Coolify

Education

  1. 2009–2016

    Umwelt-Campus Birkenfeld

    Bachelor's degree in media informatics

  2. 1998–2008

    Gymnasium am SteinwaldNeunkirchen

    Attended Gymnasium am Steinwald in Neunkirchen, graduating with the Abitur.