Full stack development on a large Rails deployment
Work as full-stack developer on a large-scale Ruby on Rails deployment, consisting of >10 applications, Docker-based environment, microservices. Initially, focus on some backend tasks. In March, together with another developer, pioneered the integration of React to realize a complicated media upload component.
Tech: Ruby on Rails, React, React-DND, rspec, capybara/poltergeist, jest, enzyme
Tooling: yarn, webpack, Gitlab, Docker, JIRA
Organisational Setting: 3 scrum teams with 4 developers each, a product owner, QA.
Blog/RSS Parser Framework as part of a Marketing application
Given a URL of a blog (of unknown underlying CMS), parse and extract the blog information.
Tech: Ruby on Rails 5 (API-only), json:api, Grape, Grape-Swagger, RSpec, FactoryGirl
Tooling: Github, Capistrano, Rubocop, JIRA
Organisational Setting: 3 developers, one product owner. When I joined, the application was barely three months old. I was tasked with the blog functionality while the other developers were occupied with different aspects.
Internal Tasks
Support on various projects, worked through React classes from React Training (see "Online Classes" below)
CMS Adapter (Ruby on Rails 5 API / Rails Active Jobs)
Test-driven development of a CMS adapter from scratch. The CMS allows to upload a file tree via rsync. The system built consists of 1) a REST API front-end (JSON-API conformant) which queues change requests to the CMS asynchronously, and 2) a rake-task/worker which executes those change requests regularly, creating a local database and serializing it to a file structure which is then rsynced to the CMS.
Tech: Ruby on Rails 5 (API-only), json:api, Grape, Grape-Swagger, RoR Active Job, RSpec, FactoryGirl
Tooling: Gitlab, Capistrano, Rubocop, Jenkins, JIRA
Responsive web front-end rebuild
Complete revamp of a front-end for responsiveness. Introduction of scss-lint. Team of 2 developers.
Tech: SCSS, Bootstrap 3, HAML, CoffeeScript
Tooling: scss-lint, Gitlab, Capistrano, Jenkins, JIRA
Portability: Safari/Firefox/Chrome/IE>=10, various Android and iOS devices
Shop system (Ruby on Rails/Spree)
Participated in the development of an e-commerce system for a startup. Full-stack development (HTML/CSS, CoffeeScript, Ruby on Rails). Also took over some project management responsibilities when the project manager fell ill. Team of 5 developers, one project manager.
Tech: CoffeeScript, Ruby on Rails 4.2, RSpec, Spree 3.0
Tooling: Gitlab, Capistrano, JIRA, docker, cloud66
Portability: Safari/Firefox/Chrome/IE>=11
Trip planner (JavaScript/Redux SPA)
Improvements to a marketing site featuring a trip planning application for an automotive company, implemented as a single page application in JavaScript/Redux. Fully responsive across iOS- and Android-devices and all major desktop browsers. Team of 2 developers.
Tech: JavaScript 6, Redux, TripAdvisor API, SASS/BEM, CSS Animations, HTML, npm
Tooling: Github, npm, Basecamp
Portability: Safari/Firefox/Chrome/IE>=10, various Android devices, iPhone 5 and above
Organisational Setting: 2 full-stack developers.
Dealer search (Google Maps JavaScript API)
As part of a website for an audio equipment provider built with Alchemy CMS/Ruby on Rails, I developed the dealer search functionality. This encompassed (from back-end to front-end) the implementation of a rake task to import the data, the controller logic (based on geokit-rails), and the complete front-end logic to enter search queries and display the results in a custom-styled map (as well as the textual results list).
Tech: Javascript, CoffeeScript, Google JavaScript APIs (Maps/Places/Autocomplete), SASS, HAML, Ruby on Rails 4.2, Alchemy CMS 3.0
Tooling: Gitlab, npm, JIRA
Portability: Safari/Firefox/Chrome/IE>=9, various Android and iOS devices
Organisational Setting: Team of 4 developers, 1 project manager.


Senior Software Developer
Full Stack Web Development with a focus on JavaScript and Ruby on Rails, working as a consultant for various clients.
Studies: Front-end web development, data mining, a bit of iOS development
XING Events GmbH
VP Technology
Led the technology (software development, IT, QA, project management) of XING Events GmbH.
Director QA
Created XING's software quality assurance team and scaled it to 25 employees.
Manager Engineering
Ruby on Rails Development. One of the first developers at XING, participated in the build and launch of the XING marketplace (now known as the jobs functionality).
Reuters AG / Odyssey Asset Management Systems
Lead Software Engineer
Development on a portfolio management system. Primarily C++. Also Java, DocBook, Solaris.
Morgan Stanley
Associate, Technology Division
Coded on a securities lending platform. Primarily C++ on Solaris. Also Perl, VBA.
London, UK
Morgan Stanley
Associate, Technology Division
Corporate trainee program. Industrial-strength C++, Java, Perl, UNIX.
New York, NY


HECTOR School of Engineering and Management
M. Sc.
Major: Information Engineering
Universität Karlsruhe (TH)
Major: Computer Science
Joint degree with ENSIMAG. Universität Karlsruhe (TH) has since renamed itself to Karlsruhe Institute of Technology (KIT)
Diplôme d'Ingénieur, M. Sc.
Major: Computer Science
Joint degree with Universität Karlsruhe (TH)
Grenoble, France
University of Northern Colorado
Major: Computer Science
Exchange year. Computer science and speech communication.
Greeley, CO
Carl-von-Ossietzky Universität Oldenburg
Major: Computer Science
“Vordiplom” in computer science, minor mathematics.

Online Classes

React.js Program

An introduction to React.js and the React ecosystem. Consists of video courses, reading assignments and, in particular, a series of assignments to create a React application. The results are on Github, see for example

Front-End Web Developer Nanodegree (Udacity)

The Nanodegree teaches front-end web development via a series of projects (see Nanodegree Structure). Projects are professionally reviewed and commented upon. Apart from the basics, it addresses responsiveness, CSS frameworks (Bootstrap), JavaScript MVC frameworks, build pipelines with grunt/gulp, and performance optimization (critical rendering path, achieving 60fps).

The source code for all my projects can be found on Github.

University of Illinois at Urbana-Champaign — Data Mining Specialization (Coursera)

This specialization teaches the basic concepts and principles in data mining and visualization. It introduces algorithms for mining structured and unstructured data (e.g. association rules, clustering, etc.). Practical work includes exposure to the MeTA ModErn Text Analysis C++ framework and a data visualization tool (e.g., Tableau).

Due to an exclusive focus on Udacity’s Nanodegree in 09/2015, I did not participate in the last class of this specialization, the Data Mining Capstone.

Where I’ve Studied and Worked