+49 160 205 0792

I'm an experienced leader & product-minded engineer deeply interested in collaboratively building useful products. With a backround spanning from small startups to scaling unicorns, I bring a wealth of experience in Elixir, Ruby and SQL complemented by JavaScript. I love Open Source, participating in the community and giving talks. My passion for performance optimization and benchmarking led me to create benchee.
In my most recent role as a Senior Staff Engineer, I led teams to success by removing obstacles, fostering a culture of collaboration and filling the gaps. Whether managing a product department of 15 or mentoring junior developers, my greatest joy comes from empowering others. I am fascinated by the human side of software development and continually strive for the optimal balance between immediate value delivery and long-term sustainability.

04/2021 — 10/2023

Senior Staff Engineer (18 months) / Staff Engineer (13 months)

Worked on a big Elixir & Phoenix monolith with a focus on the payments domain, automating processes to ensure safe, quick & reliable payments of millions while improving processes and technology company wide.

  • Implemented features to help our payments efficiency and product offering: automatic invoice payments, bank integration via PAIN XML to automate payments, enable direct debit for huge sums & allowing non local currencies
  • Design and implementation of central payment projects aiming to incorporate more providers
  • Most senior engineering individual contributor for a long time, involved in high level technology decision making
  • Introduced Background Job System to guarantee reliable asynchronous execution
  • Improved processes such as branching strategy (death to long lived branches!) and the RFC process itself
  • Advocated for hiring non Elixir engineers & setup a training camp and mentoring structure to help them succeed

08/2020 — 03/2021

Staff Developer

Engineering Lead for a team working in Ruby on Rails on topics ranging from local market adaptation, to legal and delivery promise.

08/2019 — 07/2020

Freelance Leader, Developer & Consultant

Consulting, Teaching and Development.

  • Helped a company develop their first Elixir project, introducing the technology to the team
  • Loadtested a Rails ecommerce system leading to 100x the number of concurrent checkouts with fewer servers
  • Worked on a complex microservice metrics visualization application in Ruby & NodeJS
  • Open Source work on the code coverage tool SimpleCov sponsored by Ruby Together
  • Consulted on the design, architecture & implementation of an open source project, including implementation

11/2017 — 2/2019

Tech Lead (de facto Head of Engineering)

Led a product department of 15 together with the CTO, handling the day-to-day needs of the team.

  • Helped, mentored & guided colleagues through 1o1s, pairing sessions, pull request reviews and knowledge sharing sessions
  • Ran retrospective and iteration meetings, continously adapting and improving processes
  • Gathered issues from operations and partners to define and triage solutions
  • Architected and designed features with the squads
  • Monitored application performance and fixed performance problems
  • Screened and interviewed candidates
  • Ran integration projects with customers to onboard them as quickly as possible

01/2017 — 11/2017

Senior Software Developer (de facto Team Lead)

Built and maintained applications to track shipments, plan tours and manage all required logistics data in Ruby on Rails, Elixir and Phoenix as well as JavaScript (AngularJS, React).

  • Functioned as interim-CTO during a sabbatical

01/2015 — 10/2016

Software Engineer

Built applications, helping companies blossom. Worked as part of a team or team lead on customer projects big and small. Introduced practices such as retrospectives and Continous Integration and mentored juniors.

05/2013 — 09/2018

Part-Time Freelancer

Occassional projects related to teaching programming, such as an introductory course at Humboldt-University Berlin.

05/2012 — current

Speaker, Program Committee Member & Organizer

I like to speak at conferences to share knowledge and spread ideas. I have spoken at conferences such as Øredev, Lambdadays, Polyconf and Full Stack Fest (overview of my talks). I also helped organize JRubyConf & eurucamp 2015 and was a member of the program committee of GOTO Berlin 2014.

Open Source
08/2011 — current

Creator, Maintainer & Contributor

I live and breathe Open Source and contribute to a variety of projects big and small. This is a selection of bigger projects I maintain or maintained.

  • benchee a powerful and extensible benchmarking library for elixir and erlang
  • simplecov the popular ruby code coverage tool
  • Shoes an easy to use GUI toolkit written in JRuby that I also worked on as part of Google Summer of Code

Ruby User Group Berlin
10/2012 — current

Main Organizer

A monthly meetup about Ruby and related technologies, with anywhere between 40-120 attendees. Co-created the Berlin Code of Conduct to ensure and promote a safe environment.

Rails Girls / code curious
06/2012 — current

Coach & Mentor

Rails Girls helps to diversify the tech community by helping beginners to get in touch with programming. I coach at workshops and since 2013 I also coach a weekly project group, the rubycorns, helping attendees grow into Juniors & beyond.

Hasso Plattner Institute / Blekinge Institute of Technology (Erasmus)
2008 — 2014

Bachelor & Master in IT-Systems Engineering

Final grade: 1.2 (A), Specialization in Software Architecture, Internet Security, agile & globally distributed software development

Enginneering Practices

  • agile Software Development (XP/Scrum/Kanban)
  • Test Driven Development (RSpec, ExUnit, Jasmine...)
  • Pair Programming
  • Version Control (git)


  • Object Oriented Programming (Ruby, Smalltalk)
  • Functional Programming (Elixir, functional JavaScript)
  • Web frameworks (Ruby on Rails, Phoenix)
  • Benchmarking & Performance Improvements
  • Web Technologies (HTML, CSS, JavaScript, JSON...)

Leadership & Communication Skills

  • Run and moderate meeetings such as Retrospectives
  • one-on-ones
  • Mentoring and Teaching
  • Empathy
  • Eye for process improvements and bottle necks

System Architecture

  • Database Design (SQL)
  • Domain Driven Design
  • Design Patterns
  • Monoliths, microservices and the in-between
  • APIs (modules, REST)
Native speaker
Full working proficiency
Limited working proficiency
Basic knowledge