# Peter Ullrich (@peterullrich.com)

Profile: https://sifa.id/p/peterullrich.com
Headline: Founder of Pushin.eu
Location: Leiden, South Holland, Netherlands

## About

Experienced Elixir Developer, certified Blockchain Engineer and Entrepreneur. Skilled in Team Leading, Software Architecture and Domain-driven Design. Public Speaker and Former Podcast Host of Explain Blockchain.

## Career

- **Founder at Pushin.eu** (Sep 2026 - Present)
- **AI Security Engineer at Erlang Ecosystem Foundation** (Jun 2026 - Present)
- **Founder at Letter to Yourself** (Oct 2020 - Present)
- **Senior Software Engineer at Eaglemms** (Feb 2024 - Sep 2026)
- **Founder at Indie Courses** (Dec 2023 - Sep 2026)
  NL
- **Senior Software Engineer II at Remote** (Dec 2021 - Nov 2023)
  NL
- **Full-stack Developer at kie labs, Inc.** (Sep 2019 - Dec 2021)
  Conceptualising, designing, and developing the DecisionMaker, a collaborative web application focused on facilitating efficient decision making. Stack: Elixir + Phoenix LiveView.
- **Full-stack Developer at STUDITEMPS GmbH** (Sep 2019 - Aug 2021)
  Cologne Area, DE
  Business Application Development with Elixir + Phoenix according to DDD and TDD principles.
- **Full-stack Developer at Grandcentrix** (Mar 2019 - Aug 2019)
  Cologne Area, DE
  Web Development with Elixir + Phoenix and Vue.js
- **Software Engineer at Self-employed** (Sep 2018 - Feb 2019)
  Amsterdam Area, NL
  Various client work with React-Native and Angular
- **Student Member of Programme Committee at University of Groningen** (Oct 2017 - Sep 2018)
  Groningen, NL
  Evaluating and grading the quality of the courses given at the Computing Science Faculty of the University of Groningen
- **Podcast Host at Explain Blockchain** (Dec 2017 - Aug 2018)
  Groningen Area, NL
  Producing and hosting the Explain Blockchain podcast, a podcast about Blockchain fundamentals and latest developments. Can be found on ExplainBlockchain.io or wherever you get your podcasts.
- **Masterthesis about Blockchain in Education at Quintor** (Feb 2018 - Jul 2018)
  Groningen, NL
  Exploring possible applications of Blockchain technology in the field of higher-education. Technologies researched were: Hyperledger Indy and Fabric, NEO, Ethereum. Development of prototype with Hyperledger Indy in Java
  \8. The prototype of the StudyBits project was presented at multiple conferences and meet-ups.
- **Graduate Teaching Assistant at University of Groningen** (Nov 2016 - Feb 2018)
  Mentoring, teaching, and grading Computing Science Bachelor and Master students in multiple courses at the University of Groningen. Topics included Software Engineering, Project Management, Object-oriented Programming, Cloud Computing, and Software Analysis and Design.
- **Co-Founder Blockchain Startup ForUs at Stichting ForUs** (Feb 2017 - Apr 2017)
  Groningen, NL
  After winning the Dutch Blockchain Hackathon in the Reinventing Government track, my team founded the Stichting ForUs startup and worked on extending the child support system of the Municipality of Zuidhorn using the Blockchain. I left the startup in April to focus more on my studies.
- **Web Developer at Animalwise.nl** (Feb 2015 - Oct 2015)
  Groningen Area, NL
  Development in HTML, CSS, JavaScript, and PHP to build a website including Google Analytics and an own CMS to update the texts. After creating an initial website,  I switched to creating a Wordpress website since the client wanted to manage the website herself and a well working CMS was necessary.
- **Internship at Sycade** (Jul 2015 - Aug 2015)
  Zwolle Area, NL
  Developing an macOS app called "TimePuncher" with Xcode 6 and Swift 1.2. Eventually, developing a first version of the iOS "TimePuncher" App for iOS8 with Xcode 7 in Swift 2.0 as well. I did Interface Building, most of the Swift Development, and a bit Backend Development in .Net, and otherwise everything that wasn't yet done by my colleague, Michiel Lowijs.
  
  Since TimePuncher is not published yet, you can also check out the small app "MKA NL SALAT", which I've made during this internship for one of the owners of the company.
- **Treasurer of Student Party in Faculty Council BSS at University of Groningen** (Sep 2014 - Aug 2015)
  Groningen Area, NL
  As a Council member: Advising the board of the Faculty of Behavioural and Social Sciences on a diverse range of organisational matters.
  
  As a treasurer: Managing the budget of the student party of around 2500 Euro.
- **Research Assistant at University of Groningen** (Oct 2014 - Jun 2015)
  Literature Research on Emoticons; Compiling 2 Online Studies on Qualtrics.com; Statistical Analysis of the Results; Writing up the findings in my Bachelor Thesis, which got a 9 out of 10 grade.
- **Treasurer at aegee köln** (Nov 2011 - Jun 2012)
  Cologne Area, DE
  Overviewing the monthly and yearly budget of the club. Invoicing membership fees. Managing the budgets of the projects we organised.
- **Internship at University Hospital RWTH Aachen** (Sep 2011)
  Kreisfreie Stadt Aachen Area, DE
  I worked for 4 weeks on the closed mental department of the RWTH Aachen University Clinic to gain some insight into the work as a psychologist and as a preparation for my psychology study. I worked as a nurse and looked over the shoulders of the psychologists and doctors working with the patients. It was interesting for me to see how you stabilise a patient to prepare him/her for further therapy.

## Publications

- TIL: Bike Chain Sizes — peter-learned-today.pckt.blog (Jul 2026) https://peter-learned-today.pckt.blog/til-bike-chain-sizes-tdrrqge

## Skills

### Technical
- Architecture
- Docker Products
- Elixir
- Full-Stack Development
- Programming
- Python
- REST API
- Software Architecture
- Software Design
- Software Development
- SQL
- Test Driven Development
- Testing
- Web Development
### Business
- Agile Methodologies
- Project Management
- Writing
### Interpersonal
- English
- Leadership
- Problem Solving
- Psychology
- Public Speaking
- Research
- Teaching
- Teamwork
### Other
- Business Ownership
- Business Perspective
- Computer Science
- Domain-Driven Design (DDD)
- Dutch
- Early Stage Ventures
- Higher Education
- Scalability
- Social Networking
- Social Sciences
- Start-up Leadership
- Start-up Ventures
- Start-ups Management
- Statistics
- University Teaching

## Education

- **University of Groningen** — Master (2016 - 2018)
  This is my current study, a Master degree in Computing Science with a special focus on Software Engineering and Distributed Systems. So far, I have lead groups of 4 to 5 people through many courses very successfully. I focused on Software Architecture (SA) in the beginning, but will switch to more practical courses soon since I feel that I have learned enough about SA for now and rather want to focus on more practical skills.
- **University of Groningen** — Pre-Master Education for a Master in Computer Software Engineering (2015 - 2016)
  To be qualified for a Master in Computer Science, I had to complete an individual study programme consisting of 6 Bachelor courses from the Computer Science Bachelor.
- **University of Groningen** — Bachelor’s Degree (2012 - 2015)
  My Psychology Bachelor educated me on a wide range of aspects of Psychology like Industrial and Organisational, Social, and Clinical Psychology and most of all in Statistics and Research Methods. In my final year, I worked as a Research Assistant to gain insight into Academic Research. As a minor, I took Computing Science courses, which eventually lead me to pursue a career in IT rather than Psychology. I used my acquired Team Management and Leading skills to lead teams of 3 to 10 students in my IT courses.
- **University of Cologne** — Bachelor's Degree (2011 - 2012)
  I was enrolled at the University of Cologne rather to have a swift look into Economics before leaving for Groningen to study psychology. It was interesting, but not compelling and so I moved further to study psychology.
- **RWTH Aachen University** — Bachelor's Degree (2010 - 2011)
  Civil Engineering was my first choice after finishing my High School degree in Germany as I am a very practical person, who loves to build things with my own hands. However, the study was very much focused on theoretical aspects and wasn't offering much possibilities to actually build something. Therefore, I reoriented myself towards Psychology, which is one of my two passions, the other one being Computer Science. As I could not study Psychology in Germany I researched where I could study it abroad and I found the University of Groningen. However, I just missed the application deadline and therefore had to wait a whole year until I could start the study.

## Courses

- Extracurricular Course in Entrepreneurship
- VentureLab North Start-Up Weekend 2015
- Free Writing

## Awards

- 2nd Place in Dutch Blockchain Hackathon 2018, Digital Nation Infrastructure Track (Apr 2018)
  Project was about tokenizing parking minutes and incentivizing parking outside of the city using the Ethereum Blockchain.
- 1st Place in Dutch Blockchain Hackathon 2017, Reinventing Government Track (Feb 2017)
  Project was about creating a voucher system for families of lower income. Vouchers could be used to get e.g. bikes or books for their children. Built using the Ethereum Blockchain.
- 1st Place in Poetry Slam Groningen (Apr 2014)

## Involvement

### Volunteering
- Qolora Education Centre (Apr 2016 - May 2016)
  Computer Science Teacher
  Teaching South African Xhosa children in their local High School about Microsoft Office. I lived at the Qolora Education Centre and helped construct their new buildings as well.

## Languages

- German (native)
- Dutch (full professional)
- English (full professional)

## Links

- linkedin: https://www.linkedin.com/in/pjullrich