Sven Herrmann

Erfahrungen bei 3wplusP GmbH

In my role at 3wplusP, I implemented various software projects and optimized existing systems:

• Blazor web project for book management – "Cynthy"
  As part of my work, I contributed to the redevelopment of an internal tool. The goal was to replace an existing desktop application, previously only accessible via the corporate VPN and focused solely on functionality, with a modern, platform-independent web application. The original tool allowed users to upload manuscripts and automatically generate audio files via an internal API – structured into chapters and subchapters like a real book.
  Project goals for the new web app:
  • Migration of existing features into a modern Blazor web application
  • Platform independence (responsive design for desktop, tablet, and smartphone)
  • Centralized deployment without local installations (always up-to-date)
  • Improved user experience through a modern and intuitive UI
  
  My responsibilities in the project:
  • Fullstack development of the application using Blazor:
  • Frontend: Implementation of a user-friendly interface for managing books, chapters, and text sections
  • Backend: Development of a custom RESTful API for communication with the database and audio API
  • Implementation of a custom web audio player with a highlighting feature for individual text sections, useful for corrections, feedback, or focused playback
  • Design and implementation of a structured content editing system (CRUD for books, chapters, and passages)
  • Ensuring responsiveness for mobile usage on smartphones and tablets
  • Close collaboration with internal stakeholders for ongoing requirements analysis and tool refinement
• Implementation of document management using BookStack: Analysis, installation, maintenance, and employee training for an efficient open-source DMS.
• Implementation of a ticket system using Zammad: Evaluation, setup, and maintenance of a company-specific support system, including training sessions.
• Development of an XML-PDF validator: Creation of a tool to validate XML data against company-specific rules, with error display directly in the PDF.
• nopCommerce webshop customization: Integration of company-specific logic and customer workflows, including core customizations while preserving upgradability.

My focus is on custom solutions, scalable architectures, and sustainable software development.

Erfahrungen bei Loxxess GmbH

Software Development at Loxxess – Warehouse Management System and Automation Loxxess is one of Germany’s leading logistics service providers and serves major clients such as dm-drogerie markt. In this fast-paced environment, quick, precise, and error-free information processing is essential – especially since many warehouse processes are already highly automated. Even minor mistakes can lead to delivery delays or incorrect order contents. The company relies on a proprietary warehouse management system (WMS), which is continuously developed and optimized to meet the high demands of daily operations.
Technological Environment:

• Modular microservice architecture, allowing targeted updates to specific system components efficiently and with minimal risk
• Test-driven development (TDD) with extensive unit and integration test coverage to identify errors early and ensure system reliability
• Highly structured CI/CD processes that enable fast deployment and quality assurance

My responsibilities in this project:

• Development of ASP.NET Core Web APIs to extend and optimize WMS functionality
• Implementation of business logic components closely integrated with automated warehouse processes
• Test automation: Creating and maintaining unit and functional tests based on a test-driven development approach
• Contributing to Blazor projects for developing modern web frontends for internal tools and warehouse/logistics interfaces

Erfahrungen bei 4Sellers GmbH

Software Developer at 4Sellers GmbH – E-Commerce Platform & Webshop Solutions My most recent position was at 4Sellers GmbH in Rain am Lech (Bavaria), a leading provider of comprehensive e-commerce solutions for medium-sized businesses. With 4Sellers, customers manage their entire online business through a central platform – from webshops and inventory management to logistics. The goal is to provide future-proof and high-performance systems that can adapt flexibly to market demands. I worked in the webshop systems department, where we provided our clients with modern, customizable webshops. The range includes both standardized base solutions and fully customized extensions tailored to specific business processes and product structures.
My role and responsibilities:

• Development and maintenance of backend components for our webshop solutions based on .NET Core
• Integration and extension of existing services to meet client-specific requirements for product display, shopping cart, checkout, and user management
• Integration of external interfaces (e.g., payment providers, ERP systems, shipping services)
• Optimization of existing database queries and extension of the Entity Framework model
• Close collaboration with frontend developers and project management to coordinate new features
• Active involvement in the further development of our Blazor components for internal tools and user interfaces

Working at 4Sellers was characterized by diverse requirements, direct customer feedback, and a strong focus on quality. The main priority was building a stable and scalable backend architecture that grows with the unique business models of our clients.

Erfahrungen bei Iris-Solutions GmbH

App and Web App Development at Iris-Solutions GmbH – Blazor, Xamarin & Custom Client Solutions At Iris-Solutions GmbH in Würzburg (Bavaria), I worked for around three years as a fullstack developer, focusing on web applications, mobile apps, and tailored software solutions. The company specializes in building modern applications in the fields of education, healthcare, and digital services. A key part of my work involved developing Blazor Server applications and .NET backend solutions for various client projects. I was involved in both the technical planning and the practical implementation, working closely with clients and project managers to understand requirements and deliver efficient, customized features. One particularly successful project I contributed to was the Büffeln One app, part of the well-known Bueffeln.Net app group. This educational app is widely used by students across Germany. I played a key role in its continued development, especially in integrating new features. The app was built using Xamarin, allowing it to run cross-platform on both iOS and Android. In addition, I provided technical support and contributed to the further development of an ASP.NET project created in collaboration with a hospital and as part of a clinical study. In this medical context, I was responsible for both backend and frontend development, ensuring the system operated reliably, was user-friendly, and met data protection standards. Coordinating with medical professionals and research partners was especially important in this setting.
My key areas of focus during this time:

• Development and maintenance of web applications using Blazor Server and ASP.NET
• Mobile app development with Xamarin for Android and iOS (Büffeln One)
• Backend and frontend development for medical web systems
• Close collaboration with clients on custom software projects
• Technical support and troubleshooting during live operation

This time was especially valuable for me, as I was able to work in various roles – as a backend, frontend, and mobile app developer – and contribute to practical, real-world solutions across different industries.