About Me
Know Me More
I'm René Gerritsen,a Developer
I specialize in crafting dynamic and innovative software solutions that fuel business growth and productivity. With an extensive portfolio encompassing PHP, JavaScript, and Go programming languages, I'm well-versed in various platforms including Symfony, Shopware, and Magento. My hands-on experience in the online travel industry has fostered a deep understanding of its unique needs, enabling me to devise tailored tech strategies that cater to this specific market.
Offering a comprehensive range of services from custom plugin development to API construction, I employ best practices to create highly reliable, scalable, and efficient software solutions. With my proficiency in refactoring legacy code, I can modernize your existing applications to align with the latest technology standards, thereby ensuring optimal performance and increased business agility.
Moreover, I pride myself on my ability to implement robust CI/CD pipelines. This paves the way for consistent, faster, and more reliable software releases, enhancing your team's productivity while reducing the time-to-market for your software products.
My mission is not only to meet your immediate software needs but also to lay a robust foundation for future growth and adaptability. My meticulous and client-centric approach has allowed me to deliver top-tier results within time and budget constraints. I look forward to helping your business leverage the power of technology to achieve unprecedented success.
- Name:René Gerritsen
- Email:rene.gerritsen@me.com
- Age:42
- From:Heek, Germany
20 Years
Developer Experience
7+
Programming Languages
100%
Love for Docker & Cloud
∞
Curiosity for Technology
Writings
Blog
Gitlab Virtualbox Runner
02.02.24Völliger automatisiertes einrichten eines Ubuntu Maschine als Gitlab VM Runner
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Filter, Paginate, Sort in new Backend Architecture
28.05.25Analyse und Vergleich verschiedener Ansätze zur Filterung, Sortierung und Paginierung in einer neuen Go-basierten Backend-Architektur.
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Services
What I Do?
Custom Software Development
Specializing in PHP, JS, GO, I provide tailored software solutions for your specific needs. Whether it's a custom plugin or an API, you can rely on my expertise.
E-commerce Platform Expertise
With hands-on experience in Shopware and Magento, I help businesses optimize their online presence for maximum customer reach and engagement.
Travel Industry Solutions
My deep understanding of the travel industry allows me to develop software that addresses unique challenges, driving operational efficiency and growth.
Legacy Code Refactoring
Modernize your existing applications with my legacy code refactoring service, ensuring your software aligns with the latest technology standards for optimal performance.
CI/CD Pipeline Setup
I offer robust CI/CD pipeline setups that enable consistent, faster, and more reliable software releases, enhancing your productivity and reducing time-to-market.
Business Tech Consultation
My thorough understanding of various tech platforms can provide your business with the guidance it needs to leverage the best tech solutions for your growth.
SUMMARY
Resume
My Experience
2022 - Present
Software Developer
NFON AG, München
I am responsible for developing and maintaining the core API for web and mobile applications. I am also preparing the core API for the transition to PHP 8, including unit and acceptance testing. I have collaborated on the migration of a proxy API from PHP to Golang. I am responsible for developing and implementing a Docker and Compose-based development environment and a CI/CD pipeline with Bamboo. I integrate various third-party interfaces, identify and fix security vulnerabilities and bugs.
2016 - 2022
Software Developer
Check24 Vergleichsportal Hotel, München
I was involved in developing backend APIs, refactoring legacy code, and introducing DB migration scripts and automated testing with PHPUnit. I played a key role in formulating integration guidelines for hotel providers and integrated various providers and channel managers. I focused on performance optimisation and innovative solutions in hotel cluster matching and real-time room allocation using advanced technologies such as Docker, Doctrine, Zend, PHP, and ExtJS.
2009 - 2012
Software Developer
Wildcat Deutschland GmbH, Gronau
I was responsible for the concept, development and implementation of a cross-platform RIA for jewellery customisation with 3D preview. I was responsible for providing control data for the laser and managing API-based communication with production partners, including status tracking and billing. My responsibilities also included setting up and maintaining a B2B shop based on Shopware 3. I developed plugins for closed customer groups, dealer login and article variants. I implemented customer-specific templates and designs. Furthermore, I developed an app for the then new iPad using web technologies and maintained brand shops based on xt:Commerce. I also contributed to the development of the internal fcTemplate framework and provided general IT support.
My Skills
Web Development Skills
PHP Development 90%
JavaScript 85%
Golang 70%
Bash 70%
SQL 85%
API Development 85%
Shopware Development 75%
Magento Development 70%
Full Stack Development 80%
React / ExtJs / HTML / CSS 75%
DevOps and Testing
Docker 90%
CI/CD Pipeline Implementation 90%
Unit and Functional Testing 90%
Software Engineering Principles
Problem Solving 90%
Refactoring 85%
Clean Code 85%
Software Pattern 80%
Software Architecture 85%
AI / ML
LangChain / LangFlow 60%
Python 70%
Sympy / Numpy 65%
Tensorflow / Neural Networks 40%
Design & 3D
Blender 60%
Photoshop 10%
My Work
Links
Testimonial
Client Speak
Dr. Jochen Bielek Head of Backend - Check24
“Mr. Gerritsen possesses extensive and versatile expertise, which he always applies confidently and purposefully in practice.”
Carolin Stutzmann Head of Staff - Wildcat
“Mr. Gerritsen worked for us on a project basis and was hired full-time as of October 1, 2010.”