Reginald Leonczuk-AI-Assisted Software Development | IoT | Embedded | Industrial & ERP System Integration
Check rate
Experience
ERP System Redesign (web-based)
PHP and React redesign of a web-based ERP system.
- Development of the header and parts of the navigation
- Development of various modules in React, e.g. calendar, chat, and various tables
ERPNext / WooCommerce / eBay Integrations
Docker setup & custom apps
- WooCommerce synchronization (importer & sync mechanism)
- eBay category tree, attributes & shop integration
Embedded / Reverse Engineering nRF52832
Reverse engineering nRF52832, E-scooter firmware (Odys, InMotion)
- Adjusting speed limit + feature extensions
Development C# / .NET
Co-development of a modular fleet and workshop management software based on .NET 10 / ASP.NET Core with Blazor WebAssembly frontend.
Tasks:
- Development and extension of business domain modules (packages) according to Clean Architecture / DDD principles (order management, workshop planning, route planning, defect management, etc.)
- Implementation of REST APIs and WCF/SOAP endpoints (CoreWCF)
- Database connection with Entity Framework Core
- Frontend development with Blazor WASM and Telerik UI for Blazor
- Implementation of authentication/authorization (JWT, Windows/Negotiate)
- Writing unit and integration tests (NUnit, Moq)
- Following SOLID, CQRS, and separation-of-concerns principles
Tech stack: C#, .NET 10, ASP.NET Core, Blazor WebAssembly, EF Core, CoreWCF, Telerik UI, JWT, NUnit, Moq, log4net, Docker
Development of a Web App for Car Dealerships
The browser-based app is designed as an inventory management system for car dealerships that are not tied to a specific brand. The main features are:
- API integration with mobile.de, autoscout24, and kleinanzeigen.de
- Vehicle and customer management
- Contracts and invoicing
Development of a web app for sending individual and personalized mass emails
This web app makes it possible to send mass emails.
- Sending is done through your own email address
- Import of Excel and CSV tables
- Placeholders make it possible to use different content in outgoing emails based on the imported data
Development of a web app: sales platform with Facebook connection
Browser-based sales platform built with React and TypeScript. With automated processing steps and bots, products are posted on Facebook and reactions are tracked.
- Item management
- Customer management
- Order process management
- Management of items, posts, and comments on Facebook
Development of a message server with C# (.NET), SMTP and Firebase
Concept and development of a modular message server based on C#/.NET within an existing company software. Implementation of a backend architecture with Domain, Application, and Infrastructure layers for processing and sending event messages via email (SMTP) and push notifications (Firebase).
In addition, development of a Blazor UI for managing messages, recipients, and sending logs, as well as implementation of unit tests and integration into the existing system architecture.
Managing Director, IT Admin, Project Lead, Software and Hardware Developer
Admin, IT planning, ERP rollout, software and hardware development
- Large-scale project to restructure the IT, with the requirement that all applications must be browser-based
- New Linux server (Debian) with new hardware
- Xentral ERP system
- LogicalDoc document management system
- Confluence "wiki" / knowledge base
- freePBX phone system (softphones)
- Production management system PTM – "ProductionTaskManager", custom development based on JavaScript, React, and MySQL
- (Personnel) time tracking, custom development based on PHP and MySQL
- Time is tracked with an RFID chip from the responsible staff member on any tablet (browser-based)
- A Raspberry Pi serves as the RFID card server
"Prod-IOT", custom development to improve production data capture:
Each CNC machine was equipped with an ESP32, which sends machine status data via MQTT over Wi-Fi to a server (Raspberry Pi).
- This makes it possible to record and check exact run times and quantities directly on the PC (Industry 4.0)
- Custom development of various small tools with a quality-of-life focus for accounting and payroll accounting
Rebuild of a so-called height measuring device due to a defect in the LC display. Since the LC display was no longer available, I decoded the LCD data lines and programmed a new 400 x 320 pixel TFT display using an STM32.
IBKR / Alpaca Trading Bot
Next.js frontend + provider factory
- Event-based processing with IBKR API
- Symbol search with Finnhub
IT Service
Installations and repairs in the IT field
IoT Monitoring and Data Integration Platform
Design and implementation of an IoT and monitoring architecture for collecting, processing, and visualizing sensor data from different systems. Integration of an IoT platform with SCADA systems, as well as building a scalable data pipeline for time-series data.
Implementation of data collection via MQTT, processing with Telegraf, and storage in InfluxDB. Development of Grafana dashboards for data visualization and analysis. Containerization of the entire infrastructure with Docker, plus implementation of backup and recovery mechanisms for stable operation.
Technologies: OpenRemote, Grafana, MQTT, Telegraf, InfluxDB, Fernhill SCADA, Docker.
OAuth2 Integration in ERP Systems
Login + third-party APIs
Project Lead, Hardware and Software Developer
Development of a balancing machine (mechanical structure, hardware, software)
- Mechanical build (without housing)
- Hardware: STM32-F7 with 0.8 MP TFT, plus a Siemens frequency converter connected via RS-232
- Firmware: FreeRTOS with a custom developed "ERBSTM32" framework (thread-safe), programming languages: ASM, C, and application layer with C++
- 24-bit DAQ system with a maximum sampling rate of 187.5 kHz per channel and data transfer over Ethernet.
- Software: Windows C++ / Qt
Rollout of Development System PHP / React
Setting up a new standardized remote development system that allows the use of React and PHP in the same project. A script enables the automated adding and removing of developers. VSCode is used as the IDE.
Configuration of Apache VHosts, PHP, and Xdebug: Each VHost runs its own PHP thread in the FPM thread pool, which prevents blocking
- Configuration of MySQL, Xdebug, Node, npm
- Integration and configuration of the React build system within the PHP environment: Webpack, Eslint, Typescript, Babel
- Setup of Git and various Git hooks
- Automated setup of new MySQL databases
Software Developer - IoT Barn / Agriculture: Barn Robot API / Barn Camera System (Monitoring)
Internet and Information Technology
- Interface customization and development of custom Node-RED "nodes" for operating a manure removal robot and a monitoring system
Summary
I support companies as a technical service provider in the development, modernization, and integration of software and IoT systems - with a focus on AI-assisted development, embedded systems, web applications, and interfaces between machines, hardware, ERP, and web platforms.
I combine over 15 years of experience in software development, embedded development, IoT, and mechanical engineering with modern AI-assisted development processes. My focus is on developing, modernizing, and integrating technical systems - especially where software, hardware, data, machines, and business processes come together.
In software development, I work with React, TypeScript, JavaScript, Next.js, Node.js, C#, .NET, ASP.NET Core, Blazor, PHP, Python, SQL, REST APIs, and Docker, among others. I develop web applications, backend systems, interfaces, internal tools, data imports, automations, and modular business software. I value clean architecture, understandable code, maintainability, and practical implementation.
In the embedded and IoT area, I bring experience with STM32, Raspberry Pi, ESP32, MQTT, real-time operating systems, firmware development, circuit design, and PCB design. I can connect sensors, machines, controllers, and existing systems, collect data, process it, and visualize it - for example with MQTT, Telegraf, InfluxDB, Grafana, SCADA systems, and Docker.
Another focus is the integration and extension of ERP and platform systems. This includes ERPNext, WooCommerce, eBay integrations, data migrations, API connections, automation of business processes, and custom extensions of existing software landscapes.
I use AI in a targeted way as a tool for analysis, architecture, code generation, refactoring, test development, documentation, and troubleshooting. The key point is not just using AI, but evaluating the results technically. Thanks to my experience, I can assess AI results, correct them, and integrate them productively into professional development processes.
With my background as a mechanical engineer and former managing director of a medium-sized manufacturing company, I understand technical tasks not only from a developer's perspective. I also take into account processes, cost-effectiveness, operations, maintenance, and practical feasibility within the company.
I support companies on a project basis or time basis with development bottlenecks, modernization projects, interface issues, IoT projects, embedded development, and the digitalization of industrial processes.
Skills
- Clean Code
- C (Programming Language)
- Html
- Javascript
- .Net Framework
- Php
- Vbscript
- Xml Schema
- Artificial Intelligence
- Algorithm Design
- Atlassian Confluence
- Html5
- Authentication
- Authentication Protocols
- Automation
- Bash
- Shell
- Bootstrap
- C#
- C++
- Css
- Cmake
- Database Development
- Linux
- Devops
- Dynamic Html
- Web Development
- Multi-Factor Authentication
- Eclipse
- Ecmascript
- Electrical System Design
- Embedded C++
- Embedded Systems
- Embedded Operating Systems
- Embedded Software
- Embedded Sql
- Visual C++
- Ftps
- Hypertext Markup Language
- Scada
- Form (Html)
- Web Server
- Integrated Development Environment
- Javascript Libraries
- Json
- Java Api For Restful Web Services
- Jquery
- Python
- Postgresql
- Lua Scripting
- Matlab
- Mechanical Engineering
- Machines
- Markdown
- Managed Extensibility Framework (.Net Framework)
- Microsoft Visual Studio
- Windows Presentation Foundation
- Microsoft Sql Server
- Visual Basic .Net
- Visual C
- Mysql
- Mqtt
- .Net Framework 4
- Node.Js
- Nuget
- Oauth
- Object-Oriented Javascript
- Object-Oriented Software Development
- Sql Developer
- Php Development
- Windows Powershell
- Prisma
- Prototyping (Software Development)
- Putty
- Qt Modeling Language (Qml)
- Qt (Software)
- Next.Js
- Json Web Token
- Software Engineering Process
- Shell Script
- Software Development
- Software Production
- Integration (Software)
- Technical Development
- Tftp
- Typescript
- Websites
- Extensible Markup Language
- Xml-Rpc
- Eslint
- Docker
- Container
- File Transfer Protocol (Ftp)
- .Net Core
- Php Frameworks
- React.Js
- Express.Js
- Development Programs
- Puppeteer (Software)
- Backend
- Stack Overflow (Website)
- Sass
- Webpack
- Embedded Coder
- Vba
- Programming Language
- Lodash
- Full Stack Development
- Npm (Software)
- Facebook Ads Api
- Restful Apis
- Docker
Languages
Statistics
Experience
Profile
Frequently asked questions
Have questions? Find more information here.
Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
Similar Freelancers
Discover other experts with similar qualifications and experience
Peter Kortmann
Robert Raźniewski
Matthias Spiller
Jürgen Fey
Wolfgang Dietzinger
Arne Hendricks
Jens Schneeweiß
Jörg Trappschuh
Werner Mühlmann
Stephan Giuliari
Experts recently working on similar projects
Freelancers with hands-on experience in comparable project as a ERP System Redesign (web-based)
Marc Smyk
Christof Hlipala
Patrycja Buczkowska
Manuel Kübler
Markus Steffen
Matthias Voit
Peter Achilles
Robert Wawrzyniak
Daniel Schlager
Adam Richter
Nearby freelancers
Professionals working in or nearby Ettenheim, Germany
Matthias Otterbach
Olesja Romme
Eddy Abanum
Tobias Bobka
Sebastian Freelancer
Thomas Kasemir
Melanie Huss
Janko Böhm
Nikolai Rybalkin
Edmund Niederkofler
Most recent projects
FRATCH works with many companies and recruitment agencies. Here you will find our recently posted projects and opportunities.
