+49 160 206 0792

I am a full-stack engineer deeply interested in agile methodologies, web technologies, software crafting and teaching. I contribute to a variety of open source projects (e.g. simplecov, benchee, shoes and after_do), engage in a multitude of community events (e.g. Ruby User Group Berlin), enjoy attending and speaking at conferences.


Liefery 11/2017 — now

Tech Lead

Helping customers and partners deliver packages on the same day. Mentor & guide colleagues. Design and implement new features and applications to help customers, operations and partners. Help customers integration efforts. Run retrospective and iteration meetings. Interview candidates.

Liefery 01/2017 — 11/2017

Senior Software Developer

Helping customers and partners deliver packages on the same day. Build and maintain applications to track shipments, plan tours and manage all required logistics data.

bitcrowd 01/2015 — 10/2016

Software Engineer and consultant

Building great applications, helping companies blossom. Also pushing forward open source efforts.

  • Introduced practices such as retrospectives and CI-servers
  • built the payment system for a big festival
  • Mentoring juniors

Self-employed 05/2013 — 12/2014


Software engineer and instructor.

  • Taught three introductory level web development courses at the Humboldt-University Berlin
  • Prepared material for an advanced level Ruby on Rails course
  • Built a website to show screencasts in a HTML friendly way using HTML5 and popcorn.js

Google Summer of Code (JRuby) 06/2013 — 09/2013

Google Summer of Code student

Student for the JRuby organization, working on the Shoes 4 code base improving performance, enhancing functionality and refactoring the code to achieve better readability and maintainability.

d:evolute 09/2012 — 03/2013

Ruby on Rails developer

Working on a Spree e-commerce application.

Hasso Plattner Institute 04/2010 — 07/2011

Student Assistant

Various jobs at the working group for Internet Technologies and Systems including working as a corrector for the lectures „Internet- and WWW-Technologies“ and „Internet Security“.

Ruby User Group Berlin 10/2012 — current

Main organizer

The Ruby User Group Berlin is a monthly meetup of people interested in Ruby and related topics. Each meeting consists of three presentations and a couple of lightning talks. Currently the user group attracts between 80 and 120 attendees per meeting. My main responsibilities are organizing venues, contacting speakers and moderating the meetings as well as the mailing list. Sometimes I also give presentations.

Rails Girls 06/2012 — current

Coach & Mentor

Rails Girls helps to diversify the tech community by teaching beginners how to program. I support Rails Girls Berlin by coaching at workshops and hackdays. Since March 2013 I coach a weekly project group to help interested attendees dig deeper into programming. I also helped Rails Girls Summer of Code 2013 with the team selection process, as well as mentoring two Rails Girls Summer of Code teams.

  • Helped multiple attendees to grow into a junior developer position from absolute beginners
  • Created a well received introductory presentation, which I presented multiple times

benchee 06/2016 — current


Benchmarking library for elixir I created providing extensive statistics, hooks and an extensible formatting system.

simplecov 01/2017 — current


Premiere library for code coverage in Ruby. Cleaned up open PRs/issues and keep it clean and fixes released.

Shoes 06/2012 — current


I've been part of the Shoes community for over three years now and since September 2013 I am the maintainer of the Shoes 4 project.

Conferences 05/2012 — current

Speaker, Volunteer and Program Committee Member

I like to go to conferences, speak at them and helped organize some of them.

  • Speaker at Lambdadays 2018, Polyconf 2017, Full Stack Fest 2016, Rubyconf Portugal 2016, Rubyconf 2015 & more
  • Member of the program committee and a track host for "Monoliths and Microservices" and "Software Craftsmanship" at GOTO Berlin 2014
  • International Volunteers Program Chair at XP 2012
  • Volunteer at Agile Dev Practices 2013, GOTO Berlin 2013, JRubyConf 2014 and eurucamp 2014

Hasso Plattner Institute 2011 — 2014

Master in IT-Systems Engineering
Software architecture
Collaborative Learning in a Massive Open Online Course environment
Final Grade:
1.2 (A)

Blekinge Institute of Technology 08/2011 — 03/2012

ERASMUS Master in Software Engineering
Agile software project management

Hasso Plattner Institute 2008 — 2011

Bachelor in IT-Systems Engineering
Software architecture and online security
Event Adapters and Correlation in Process Engines
Final Grade:
1.3 (A-)
  • Participated in a nine month, near full time team project developing a process engine
  • Participated in a fifty person Scrum project to build a Customer Relationship Management system

Friedrich Schiller Gymnasium 2001 — 2008

Secondary School
Computer science and mathematics
Final Grade:
1.0 (A)


  • Object Oriented Programming (Ruby, Smalltalk, Java)
  • Functional Programming (Elixir, functional JavaScript)
  • Web frameworks (Ruby on Rails, Phoenix)
  • Design Patterns

Web Development

  • JavaScript/CoffeeScript
  • React
  • Angular
  • HTML
  • CSS

Enginneering Practices

  • eXtreme Programming
  • Scrum
  • Test Driven Development (RSpec, EXUnit, Jasmine...)
  • Pair Programming
  • Version Control (git)

Soft Skills

  • Retrospectives
  • one-on-ones
  • Mentoring and Teaching
  • Project Inception
Native Speaker
Full working proficiency
Limited Working proficiency
Basic knowledge