Curriculum Vitae

• Full-stack development of booking and marketing systems using Python/Django backend and React/TypeScript frontend
  rocketbooking.de
• Integration of payment providers (Stripe, PayPal) and Google OAuth authentication
• DevOps responsibilities including CI/CD pipelines with GitHub Actions and Ansible, Docker containerization
• Established Scrum methodology and trained team members in agile practices
• Led onboarding and mentoring of new developers, ensuring smooth team integration

• Identification of electrical utility tasks using orthophotos and image recognition
• Support in creating scenario datasets for EU research projects
• Applied machine learning techniques for image analysis

• WordPress development - custom themes, plugins, SEO optimization, and server configuration
• Full-stack mobile app development using Meteor framework, MongoDB, AngularJS, and Ionic
• Enterprise application development with Angular 7, TypeScript, Electron, and Node.js
• Frontend development with React, Redux, ES6, and backend with PHP7/Symfony
• LAMP stack development with custom PHP MVC framework, MySQL, nginx/Apache configuration
• Mail server setup (Postfix/Dovecot) and custom CMS/API development with search engine implementation

• Frontend development with React, Redux, and ES6 JavaScript; Backend with PHP7/Symfony Silex
• Database development with MariaDB and RESTful API design including AWS and mail API integrations
• Lead developer for WordPress custom theme and plugin development
• Agile development using Git feature-branch workflow and Jira for sprint planning

• Developed embedded systems for automotive applications
• Programming in C for microcontrollers
• Hardware-software integration and testing

• Founder of the Flug- und Modellsport Verein Frechen e.V. (FMF) in 2017
  fmfrechen.de
• Since February 2017 voluntarily active as first chairman of the association
• Organisation of an open day for drone pilots in the Cologne area
• Voluntary organisation of workshops with drones

• Regular courses for interested children and young people during the holidays
  lnu-frechen.de
• Courses thematically based in the areas of flying drones (control, construction and technology), computer science and programming
  grundkurs.daniel-zelenak.de
• Developed interactive Python programming course using Titanic dataset for teaching data analysis and machine learning
  titanic.daniel-zelenak.de

• Annual participation as a speaker at my former high school, informing interested students about studying computer science

Developed hospital bed management system with patient-to-room assignment optimization. Developed Django REST API backend with PostgreSQL database and React Admin frontend using TypeScript and Material-UI. Integrated Gurobi optimization solver for efficient bed allocation algorithms. Implemented patient management with diagnosis tracking, historical data recording, and real-time room assignment visualization.

Development of optimization heuristics for the "Heliostat Wiring Problem", including ILP formulation, Delaunay triangulation-based approaches, and local search algorithms. Implemented mathematical heuristics achieving solutions within 5% of optimal bounds on real-world solar heliostat plant instances.

Team project implementing an autonomous package delivery system solving the Vehicle-Routing-Problem (VRP) with time-efficient pickup strategies. Developed graph-based map data structures with compile-time route calculation using Dijkstra's algorithm, collision detection and avoidance systems, and real-time visualization using Grafana. Applied Scrum methodology and C++ for embedded systems programming.