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I'm Martin (Rudra) Grellmann.-image

I'm Martin (Rudra) Grellmann.

I am an innovative and a certified Full-stack web developer and Full-stack software engineer, with the Knowledge as SAP Technical Consultant.

Experienced in full-stack web development with over 20 years in the field Proficient in HTML, CSS, React, JavaScript, Node.js, PHP, and MySQL. Possess 7 years of experience in Linux administration and 3.5 years in business software development, including 2.5 years in SAP technology.

I am committed to continuous learning and innovation, with a strong focus on clean code and S.O.L.I.D principles. Skilled in designing, testing, and maintaining web systems, with a proven track record in business consulting and Industry 4.0 applications.

CV as PDFCV in detail as PDFContact
MArtin Grellmann, Full-Stack software engineer

About me

With 20 years experience, I develop reasonable solutions for complex challenges, adhering to Clean Code and S.O.L.I.D. principles to ensure high software quality.

  • Location:Povoado do Moinho, Alto Paraíso de Goiás, Brazil
  • Study:Certified Full-Stack Web Developer
  • Nationality:German / Brazil Residence
  • Job Training:Full-Stack Web Developer (2021)
  • Age:49
  • Job Training:Scrum Master PSMI (2020)
  • Interests:Travel, Family, Music
  • Job Education:Industrial clerk (2004)

Summary

My career is marked by the commitment to continuous learning. I deliver high-quality, reliable software solutions. I thrive in collaborative environments and am dedicated to developing innovative and efficient solutions.

SAP Technical Consultant, SAP Full-Stack Development

BA Business Advice GmbH, Germany•February 2022 - Present

Business consulting and SAP solutions expert with extensive experience in SAP ABAP (Clean Core), SAP MII, SAP UI5 Freestyle, SAP Fiori Elements, SAP S4/HANA Public Cloud Side-By-Side Extension, SAP RAP, SAP CAP, OData v2, OData v4, and ABAP CDS. Proficient in implementing migrations from ERP to S/4 HANA and refactoring existing applications. Also experienced in JavaScript, TypeScript, and Jest.js for the UI5 framework.

Software Developer and Linux Administrator

Sengicon GmbH, Germany•February 2021 – January 2022

Focused on full-stack software development and Industry 4.0 applications. I possess extensive experience in refactoring PHP code and developing React web frontends with Material Design. Additionally, I have a strong background in the installation, configuration, and administration of LAMP-stacks under Linux environments. My skill set also includes conducting comprehensive application tests using PHPUnit and Jest.js, as well as database modeling and integrating RESTful APIs with PHP.

Webmaster (with development tasks)

Ferienhaus-Vermittlung fincaferien.de GmbH, Germany•April 2002 – December 2019

Dynamic and results-driven web and network enhancer with extensive experience in web development, network management, and search engine optimization. Adept at leveraging a diverse skill set to drive traffic, improve user experience, and maintain robust network systems. Demonstrated expertise in HTML, CSS, PHP, Drupal, Git, Jira, SEO, SEA, and Linux administration. Proven ability to monitor analytics, develop effective SEO strategies, and perform comprehensive website audits. Skilled in managing both Linux (Samba) and Windows networks to ensure seamless operations.

Skills

The value is based on experience. Additional I add the years of experience and in which role I used that skill mostly.

Techniques / Administration

Backend development

Frontend development

Frameworks / CMS

Database modelling

SAP Technologies

Work

SAP Technical Consultant, SAP Full-Stack Development

BA Business Advice GmbH, Oldenburg, Germany•February 2022 - Present

Business consulting and SAP solutions.

Delivered expert SAP solutions tailored to client needs. Leveraged extensive technical skills to realise Solution in SAP landscapes and enhance business processes. Provided comprehensive business consulting services and SAP solutions. Specialized in SAP ABAP, SAP MII, SAP UI5 Freestyle, SAP Fiori Elements, and SAP S4/HANA Public Cloud Side-By-Side Extension. Successfully implemented migrations from ERP to S/4 HANA and refactored existing applications.

Technical Skills
  • Proficient in SAP ABAP (Clean Core), SAP MII, SAP UI5 Freestyle, SAP Fiori Elements, SAP RAP, SAP CAP, OData v2, OData v4, and ABAP CDS.
  • Experienced in using JavaScript, TypeScript, and Jest.js for the UI5 framework.
  • Extensive experience with S4/Hana Cloud - Public Edition: Side-By-Side Extension and S4/Hana Cloud - Public Edition: Developer Extension.
  • Competent with SAP BTP (Business Technology Platform).
Additional Information
  • Successfully implemented migrations from ERP to S/4 HANA and refactored existing applications.
  • Demonstrated proficiency in JavaScript, TypeScript, and Jest.js for the UI5 framework.
Achievements
  • Implemented migrations from ERP to S/4 HANA.
  • Refactored existing applications to enhance performance and maintainability.
  • Experienced in problem-solving within SAP technology and customizing ABAP Application und UI5, consistently delivering innovative solutions to complex challenges.

Skills

  • SAP ABAP (Clean Core)
  • SAP MII
  • SAP UI5 Freestyle
  • SAP Fiori Elements
  • S4/HANA Cloud - Public Edition: Side-By-Side Extension
  • S4/HANA Cloud - Public Edition: Developer Extension
  • SAP RAP
  • SAP CAP
  • oData v2
  • oData v4
  • ABAP CDS
  • ABAP BTP

Software developer and Linux administrator

Sengicon GmbH, Leipzig, Germany•February 2021 - January 2022

Full-stack software development and Industry 4.0 applications.

Developed and maintained full-stack applications, ensuring seamless integration between front-end and back-end systems. Implemented Industry 4.0 solutions to enhance automation and data exchange in manufacturing technologies.

Technical Skills
React Web Frontends with Material Design
  • Created dynamic and responsive web frontends using React and Material Design principles.
  • Enhanced user experience through intuitive and visually appealing interfaces.
  • Developed a custom router in React to manage client-side navigation efficiently.
PHP Code Refactoring
  • Refactored legacy PHP code to improve performance, maintainability, and scalability.
  • Utilized Composer for dependency management and PHPUnit for unit testing, ensuring robust and error-free code.
Database Modeling
  • Designed and implemented relational database models using MySQL, MariaDB, and PostgreSQL.
  • Ensured data integrity and optimized database performance through efficient schema design and indexing.
Integration of RESTful APIs with PHP
  • Developed and integrated RESTful APIs using PHP to facilitate communication between different software systems.
  • Ensured secure and efficient data exchange between client and server applications.
Application Testing
  • Conducted rigorous application tests using PHPUnit for PHP and Jest.js for JavaScript to ensure high-quality software delivery.
  • Identified and resolved bugs and performance issues through systematic testing and debugging.
LAMP-Stack Management
  • Installed, configured, and administered LAMP-stacks (Linux, Apache, MySQL, PHP) to support web applications.
  • Expertise in setting up and managing Linux servers, including CentOS as a virtual machine (VM).
System Administration
  • Installation, configuration, and administration of Linux and LAMP-stacks.
  • Hardening and managing CentOS as a virtual machine (VM).
Additional Information
  • Proficient in version control systems like Git.
  • Strong understanding of web security practices and performance optimization.
  • Excellent problem-solving skills and attention to detail.
  • Ability to collaborate effectively with cross-functional teams.
  • Ability to collaborate effectively with cross-functional teams.
  • Experienced in problem-solving within software development, consistently delivering innovative solutions to complex challenges.
Achievements
  • Implemented Industry 4.0 solutions to enhance automation and data exchange in manufacturing technologies.
  • Distinguished myself in particular by successfully converting an outdated PHP web application to a modern PHP REST backend with a connection to an independently created new React-Web-Frontend including Database modelling.

Skills

  • PHP
  • Composer
  • PHPUnit
  • JavaScript
  • Typescript
  • React.js
  • Jest.js
  • Database modeling
  • Database management
  • MySQL
  • MariaDB
  • PostgreSQL

Webmaster (with development tasks)

Ferienhaus-Vermittlung fincaferien.de GmbH, Bockenem, Germany•April 2002 - December 2019

Fincaferien was one of the first German agencies to successfully broker vacation homes online.

Extensive experience in web development, network management, and SEO. Skilled in driving traffic, improving user experience, maintaining robust networks, and managing Linux.

Technical Skills
Web Development
  • Developed and maintained websites using HTML, CSS, PHP, and Drupal.
  • Customized Drupal modules to meet specific client needs and enhance functionality.
  • Proficient in creating and maintaining web pages with a strong understanding of usability design principles.
PHP, Drupal
  • Experienced in developing and managing dynamic web applications and Drupal content management systems, including custom module development.
Project Management
  • Utilized Git for version control and Jira for project management to facilitate smooth and efficient development processes.
  • Collaborated with cross-functional teams to deliver projects on time and within scope.
Linux Administration
  • Competent in managing Linux-based systems, including Samba for file sharing and network management.
  • Managed Linux (Samba) and Windows networks, ensuring secure and efficient operations.
  • Performed regular maintenance and troubleshooting to minimize downtime.
SEO Strategies
  • Developed and implemented SEO strategies to boost website traffic and improve search engine rankings.
  • Conducted thorough website audits to identify areas for improvement.
Analytics Monitoring
  • Monitored website analytics to track performance metrics, user behavior, and campaign effectiveness.
  • Utilized data insights to optimize user experience and content strategy.
Additional Information
  • Self-taught and adept at acquiring the know-how to solve complex problems in Web Design, PHP, Drupal, SEO / SEM and Project management. .
Achievements
  • Successfully increased organic traffic through targeted technical SEO strategies.
  • Enhanced website performance and user experience, resulting in a reduction in bounce rate through implementing usability methods recommended by Jacob Nielsen.

Skills

  • HTML
  • CSS
  • Usability
  • Drupal
  • Git
  • Jira
  • Linux Administration
  • Samba
  • SEO
  • SEA
  • Analytics Monitoring

Stagehand

As freelance work in Germany: Berlin, Hanover, Braunschweig, and Wolfsburg•August 1998 - Juli 2002

At events, concerts, congresses, corporate events and trade fair appearances

In order to comply with the safety protocols, I had completed a safety training for rigging technology.

Education

Full-Stack Web Developer, Practical Internship

Sengicon GmbH, Leipzig, Germany

Practical Internship to get deep into best practises.

Practical training covered best practices in LAMP-Stack, Javascript, PHP, MySQL and Linux-Administration.

Certification of Full-Stack Web Developer

Indisoft GmbH, Leipzig, Germany

Training covered best practices in responsive web design, Javascript and PHP, MySQL, content management, e-commerce, and online marketing, including SEO, SEA and Google Analytics. Included a Scrum Master (PSMI) certificate.

Vocational training as an Industrial Clerk

DAA GmbH, Hildesheim, Germany

Focused on business processes, commercial management and control, and economic and social studies.

Interests

  • I am interested in electronic music, a DJ since 3 decades and developing our property in Moinho, Alto Paraíso de Goiás.
  • I live in Germany for a small part of the year, but I spend most of my time in Brazil.
  • I have an official Brazilian National Migratory Registry Card (CRNM) with an unrestricted work and residence permit.

Freelance

In principle, I am open to freelance offers. Feel free to contact me via email.


I've extensive experience and skills in responsive web design, full-stack development, JavaScript backend development, database modelling, PHP development, SAP UI5 Freestyle development, ABAP development, S/4 HANA Cloud - Public Edition Extensions, and BTP - Node development, making me a strong candidate for various freelance opportunities.

  • Clean Code
  • S.O.L.I.D. - Principle
  • HTML / HTML 5
  • CSS / CSS 3
  • Javascript
  • Typescript
  • PHP, PHP 8
  • Drupal
  • Wordpress
  • E-Commerce
  • Node.js
  • Composer
  • React (without Redux)
  • Material Design
  • SAP ABAP (Clean Core)
  • Python
  • SAP UI5
  • SAP Fiori
  • SAP MII
  • SAP BTP Side-By-Side Extension
  • SAP BTP Side-By-Side Extension

I am proficient with the technical stack

Full-Stack Development

For me, full-stack development means that new technologies can be learned quickly based on existing knowledge.

Cloud Development

The future is now, and all previous technologies have led to the cloud. That's why there's no way around developments in the cloud.

Clean Code and Microservices

Embracing clean code, S.O.L.I.D principles, and microservices enhances software maintainability, scalability, and reliability, fostering an efficient development environment.

Get in touch.

Ways to contact me: