Sven Woltmann – about me

The facts in a nutshell

Programming has been my passion since I was eight years old – that was 35 years ago. Via Basic, Turbo Pascal, Delphi and C++, I came to Java in 1996 – 22 years ago.

My personal focus is on backend development, especially on the technologies and frameworks mentioned below.

I completed my computer science studies at the TU Ilmenau in 1999 as a graduate computer scientist with distinction. I have been a member of Mensa Deutschland e. V. since 2002.

I have founded several startups and since 2009 I have been a board member and CTO of AndroidPIT, the world’s largest multilingual Android community, with responsibility for the IT team with up to 15 employees and – until today – as part of the development team.

What drives me

• Focused on complex problems solving and – in constant dialogue with stakeholders, with love for detail and yet in adequate time – creating elegant, intuitive, efficient, scalable, secure and maintainable solutions – and then seeing how these are used by users.
• Planing and implementing complex systems – and then observing how their parts and subsystems interact successfully with each other.
• The freedom to use technologies that can solve the task most efficiently – taking the macro architecture into account.
• The continuous expansion of my own boundaries through new challenges and learning new technologies, principles, patterns and practices as a result.
• Discovering how complex tasks have been solved by other developers, thereby expanding my own knowledge and skills.
• Surprising other developers with new approaches to solutions, encouraging and to inspiring them to create elegant, intuitive, efficient, and maintainable code themselves.

Main areas of expertise

• Java (Advanced Topics: Reflection, Concurrency, Performance, Memory Model, GC)
• Spring Framework (Spring Boot, Spring Cloud, Spring Data)
• Microservices with Kubernetes, Docker, Spring Cloud
• Elasticsearch, Logstash / Filebeat, Kibana (ELK)
• Relational database management systems, MySQL, JPA, Hibernate
• Reactive Streams (RxJava, Project Reactor)
• Design Patterns
• Clean code (SOLID principle)
• Code quality (PMD, FindBugs / SpotBugs, Checkstyle, Sonarqube)
• Test-driven development (JUnit, Hamcrest, Mockito, Powermock, Testcontainers)
• DevOps (Ansible, Jenkins, Chef)

Career and technologies

Since 2009:

Board member and CTO of Fonpit AG in Berlin, operator of the world’s largest multilingual Android community, AndroidPIT with approx. 50 employees.

• Setting up the agile IT team (Scrum) and responsibility for up to 15 employees.
• In September 2018: upgrade of the code base to Java 11, the Java 9 module system “Jigsaw”, Spring 5.1, Spring Boot 2.0 and Hibernate 5.3.

• Development of a high-performance, scalable and customizable content management system for AndroidPIT since 2009 – with the Spring Framework, Hibernate ORM, Tomcat, MySQL and Elasticsearch in the backend.
• Development of the native advertising format “NEAds – Native Engagement Ads” since 2016 – implemented them as a Microservice architecture with Spring Boot, Spring Cloud, Netflix OSS, Elasticsearch and RxJava – and operated in a Kubernetes cluster.

• Development of the AndroidPIT App Center, a Google-independent app store for Android apps with various payment methods and the ability for app developers to offer discounts and promotions, – pre-installed on devices of many manufacturers in 2010.
• Development of the first web directory of Android apps in 2009 – even before the Google Play Store existed as a website – by reverse engineering the Android App Store.
• Setting up CI/CD pipelines with Jenkins and the Jenkins Job DSL.
• Automation of the configuration and administration of the IT infrastructure with Ansible.

2004 – 2009:

Founder, board member and CTO of eleisure AG in Karlsruhe, a holding company for online gaming.

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Development of the game rental platform “GameAbo”, the browser-based MMOG “Feenix – The Age of Pirates”, which was voted Browser Game of the Year 2005 by 50,000 readers of the online magazine “Galaxy-News”, and the browser-based 3D flirt community “Bailamo”. Development of the backends based on Java, Spring Framework, Hibernate ORM, Tomcat and MySQL. Development of the Bailamo 3D Frontend as a Java Applet with OpenGL and JOGL.

2002 – 2004:

Team leader for Windows client development at 1&1 Internet AG in Karlsruhe.

Responsible for the further development of the SMS Manager and the re-implementation of the entire SMS backbone of the United Internet Group based on Java, JMS and JBoss (now WildFly).

2000 – 2002:

Founder, Managing Director and head of software development of W+R Software GmbH in Regensburg, developer of GMX SMS Manager, the first paid online SMS service in Germany.

Implementation of the backend with Java, JDO, Tomcat and Oracle DB. Development of the frontend with Borland C++ Builder.

Acquisition of the company by 1&1 Internet AG in October 2002.

1999 – 2000:

Head of software development at JFAX Germany in Regensburg, the local branch of J2 Communications, provider of a Unified Messaging platform.

Setup of the German portal “jfax.de” with Java, JSP, JRun and Oracle DB.

In August 2000, the business was handed over to the parent company in the USA.

1999:

Founder and CTO of Cleverlearn Inc., provider of an online language learning platform based in Los Angeles.

Development of the backend functionality with Java, the servlet engine JRun and Oracle DB as database system. Development of the frontend with Visual C++.

1994 – 1999:

Studied Computer Science at the Technical University Ilmenau with a focus on practical computer science, algorithms and data structures, and database systems.

Diploma thesis with the title “Conception, comparison and evaluation of different approaches for the data management of an adaptive agent based on predictive data mining” at Amazon in Seattle, USA.

Graduated as Diplom-Informatiker with distinction after 9 semesters.

References

ID4me Summit, August 2018:

• at heise online (in German):
  Login mit ID4me: Dezentrales Single Sign on fürs Internet
  (Download als PDF-Datei)
• at datensicherheit.de (in German):
  ID4me: Management von digitalen Identitäten
  (Download als PDF-Datei)