Project References

Successful backend projects across various industries – from API migration to cloud infrastructure

Selected Projects

SaaS Platform Marketing Automation (Germany)

09/2023 – present

Multi-Tenant SaaS API Architecture for Automated Marketing Content

Further development of a scalable multi-tenant SaaS API architecture with automatic scaling, testing and improvement of stability and performance.

  • Multi-tenant database schema design
  • Performance & stability improvements
  • PHP + framework upgrade of the newly structured REST API
  • Comprehensive, automated API testing
PHP Symfony MySQL Redis REST APIs AWS AWS ECS Docker CI/CD K6 Swagger Bitbucket Datadog Atlassian SaaS
"He carries out all tasks completely independently, very carefully and in a well-planned manner." (translated) – CTO, anonymized

Marketplace with over 12,000 Merchants (Germany | International)

10/2013 – 09/2016

Responsible API Development | Head of 3rd-Level Support

Modernization and performance enhancement of API connections/import functionalities for more than 12,000 online merchants with increased robustness.

  • Implementation/planning of REST APIs and internal app APIs
  • Plugin & connection support for various shop systems
  • Integration of various payment service providers & shop systems
  • Pioneer in Apple Pay implementation
PHP CakePHP MySQL Redis REST APIs AWS AWS RDS Docker Jenkins Swagger Bitbucket Atlassian Elasticsearch Kibana Logstash
"Mr. Gengel has worked his way into the areas of responsibility with great success and commitment and can achieve above-average success due to his extensive and well-founded knowledge." (translated) – Head of HR, anonymized

E-Commerce Company (Germany | International)

10/2016 – 02/2017

Development of Product Information Management System

Development of a robust and high-performance PIM as a central solution for previously distributed product data.

  • Consolidation of fragmented product information
  • Strategic planning & implementation of database architecture
  • Architectural planning & development of the API
  • High-availability Redis cluster for product caching
  • Implementation & planning of a webhook system
PHP Symfony Silex Yii2 MySQL Redis RabbitMQ REST APIs Apache Swagger Atlassian Elasticsearch Kibana Logstash

Neo-Bank (Germany)

02/2020 – 06/2020

Improvement of Communication Security

Strengthening data security between internal services and third-party providers – to minimize business-critical risks.

  • Ensure manipulation/read security of data packets
  • Create several proof-of-concepts
  • Consulting other teams/service providers for implementation
  • Testing using Postman
PHP Symfony PHPUnit MySQL Redis Nginx Docker Ansible Postman Bitbucket Atlassian

Realize your project?

Let's discuss your backend challenges and develop a tailored solution together.

Discuss Project