DI & .NET Architectural Cleanup
Client: Insurance · Düsseldorf
Refactored service architecture — removed static patterns, fixed DI lifetime mismatches (Scoped vs Singleton), eliminated tight coupling and reorganized Startup registrations.
C# / .NET
Azure DevOps
Visual Studio
Own Product
exponde – "experts on demand" Web Platform
Client: pixelquadrat GmbH · Düsseldorf
Full pre-launch of a web platform plus iOS & Android mobile apps. Led international team, coordinated design agencies, defined development guidelines, managed full budget.
C# / .NET
JavaScript
Azure
MS SQL
iOS
Android
Barrier-Free Strengthening Act (BFSG)
Client: Insurance
WCAG 2.1 (AA) / EN 301 549 compliance across websites, mobile apps and digital documents. Accessibility audits, screen reader tests, keyboard navigation, vendor management.
WCAG 2.1
C# / .NET
JavaScript
Accessibility Insights
ARC Toolkit
Own Product
mattopen.com – Social Bookmarking Platform
Own product · mattopen.com
Full-stack social bookmarking platform: save links, curate lists, follow users, discover trending content. Includes TOTP 2FA, DE/EN i18n, drag & drop, dark mode, Google Analytics, AdSense, AWS SNS notifications and a custom timeline feed powered by the moTimeline library.
Next.js 16
TypeScript
React 19
Tailwind CSS v4
Prisma
MySQL
next-auth
AWS SNS
Corporate Customer Business (FKG)
Client: Insurance · Stuttgart
Responsive mobile-first frontend, complex UI components aligned with CI/CD guidelines, cross-system application integration and architectural consulting.
C# / .NET
JavaScript
Ajax
Azure DevOps
Rate Calculator & Forms for End Customers
Client: Insurance · Stuttgart
XML-driven application sheets, responsive UI design and programming, prototyping and architecture consulting for insurance customer-facing tools.
JavaScript
jQuery
C#
Sass
XML
Corporate Customer Portal – Design & Usability
Client: Insurance · Düsseldorf
Responsive frontend, Living Style Guide maintenance, Usercentrics CMP integration, UI framework expansion and backend C# .NET development.
C# / .NET
Sass / SCSS
Usercentrics
BrowserStack
bKV Corporate Portal – Mass Processing (MVF)
Client: Insurance · Düsseldorf
Architecture consulting, Bipro layer development, core function implementation and system analysis for mass processing capability.
C# / .NET
Kanban
OOP
New CD & System Migration Consulting
Client: Insurance · Stuttgart / Remote
Frontend technology consulting, architecture design and documentation, system implementation, testing and production deployment.
C# / .NET
AJAX
CSS / Sass
UX/UI
Complex Cross-System Business-Critical Applications
Client: Insurance · Stuttgart
Full software lifecycle from conception to deployment. Architecture design, development standards, enterprise application landscape contribution, partial project management.
C# / .NET
JavaScript
CSS3 / HTML5
Sass
SSMS
UX/UI Consulting – .NET C# Frontend
Client: Insurance · Stuttgart
Evaluation of existing web applications, responsive frontend development, UI prototyping, unit testing and technical documentation.
C# / .NET
BEM
Sass
UX Design
Bootstrap
Self-Service Portal MSP
Client: menovo GmbH · Düsseldorf
Business process analysis, ETL development, SQL views and procedures, UI design and programming, international sub-project coordination.
C# / .NET
MS SQL
JavaScript
Bootstrap
CRM
Web Portals & Internet Presence – Various Clients
Client: Various · Düsseldorf
Full delivery of web portals and sites: concept, development, supplier management and client consulting across multiple projects over 4 years.
HTML5 / CSS3
JavaScript
Bootstrap
UX/UI
Product Presentation App – Medion LifeTab
Client: Medion AG · Essen
Standalone offline application for the LifeTab tablet, developed for point-of-sale promotion. UI implementation in close coordination with the client.
HTML5
CSS3
jQuery
MS SQL
nopCommerce Theme Creation
Client: menovo GmbH · Düsseldorf
Style guide creation, CI/CD design adaptation and custom nopCommerce theme development.
HTML5 / CSS3
C#
Bootstrap
Web API
Open Source
moTimeline – Responsive Timeline JS Library
npm: motimeline · github.com/MattOpen/moTimeline
Open-source JavaScript library (v2.12, MIT) for rendering responsive two-column timeline layouts. No dependencies, built with Vite, distributed via npm as ESM/CJS/UMD. Published since 2014, actively maintained and used in production on mattopen.com.
JavaScript
Vite
npm
ESM / CJS / UMD
MIT License
New CRM System – Make-or-Buy Analysis
Client: Menovo GmbH · Düsseldorf
OpenSource vs. in-house evaluation, management reporting, technical concept analysis, vendor evaluation and workshop facilitation.
Business Analysis
Vendor Evaluation
nopCommerce
Consolidated Reporting SQL
Client: menovo GmbH · End clients: Henkel, Vodafone, 3M
Data source consolidation, performance-optimized SQL reporting across managed services and software distribution environments.
MS SQL Server
SSMS
ETL
Reporting
11 Years
Business Helpdesk 1st / 2nd / 3rd Level
Client: Johnson & Johnson · All German Subsidiaries · Neuss
Setup and 11-year operation of multi-level helpdesk in two-shift operation. CRM and database model development, SLA management, staff leadership, contract negotiations.
MS SQL Server
ARS Remedy
CRM Dev
SLA Mgmt
IT Service Department Consolidation
Client: Johnson & Johnson (Pharma) · Düsseldorf / Neuss
Centralization of IT departments from 4 subsidiaries (hundreds of employees). Process restructuring, SLA creation, stakeholder workshops, executive presentations.
Process Analysis
Stakeholder Mgmt
SLA
Fixed-Line, Mobile & Fleet Management Consolidation
Client: Johnson & Johnson · Neuss
Consolidation of telecom processes (ISDN/DSL, Vodafone), procurement centralization, CRM and database model development, SLA creation and reporting.
MS SQL Server
CRM Dev
Database Modeling
Reporting
