Aug 2022 – Oct 2023 · 1 yr 2 mos · Germany

Feb 2019 – Oct 2022 · 3 yrs 8 mos · Düsseldorf und Umgebung, Deutschland

Jun 2018 – Jul 2021 · 3 yrs 1 mo · Düsseldorf und Umgebung, Deutschland

Jan 2016 – Dec 2017 · 1 yr 11 mos

• Hazelcast is the leading open source in-memory data grid. As a free open source download under the Apache license it enables any developer can include in minutes to build elegantly simple mission-critical, transactional, and terascale in-memory applications. The company provides commercially licensed Enterprise editions, Hazelcast Management Console and professional open source training, development support and deployment support. The company is privately held and headquartered in Palo Alto, California.

Jan 2015 – Dec 2015 · 11 mos

• Hazelcast is the leading open source in-memory data grid. As a free open source download under the Apache license it enables any developer can include in minutes to build elegantly simple mission-critical, transactional, and terascale in-memory applications. The company provides commercially licensed Enterprise editions, Hazelcast Management Console and professional open source training, development support and deployment support. The company is privately held and headquartered in Palo Alto, California.

Feb 2014 – Jan 2015 · 11 mos

• Hazelcast is the leading open source in-memory data grid. As a free open source download under the Apache license it enables any developer can include in minutes to build elegantly simple mission-critical, transactional, and terascale in-memory applications. The company provides commercially licensed Enterprise editions, Hazelcast Management Console and professional open source training, development support and deployment support. The company is privately held and headquartered in Palo Alto, California.

Sep 2013 – Feb 2014 · 5 mos

• Hazelcast is the leading open source in-memory data grid. As a free open source download under the Apache license it enables any developer can include in minutes to build elegantly simple mission-critical, transactional, and terascale in-memory applications. The company provides commercially licensed Enterprise editions, Hazelcast Management Console and professional open source training, development support and deployment support. The company is privately held and headquartered in Palo Alto, California.

Oct 2012 – Dec 2020 · 8 yrs 2 mos

• As an OffHeap cache solution Apache DirectMemory needs to have a great, scalable and fast backend. I am mostly working on extending and designing the buffer backend and on how to manage high loads of concurrency with near-zero contention.
• In addition to that I contributed Apache Lightning as a subproject of DirectMemory. Lightning is a fast, threadsafe POJO serializer for small, efficient and lightning fast serialization of transport objects. It uses bytecode generation and direct memory access to achieve these goals and will be integrated into DirectMemory as one of the integral pars.

Apr 2012 – Oct 2013 · 1 yr 6 mos · Düsseldorf und Umgebung, Deutschland

• Being part of the backend team I am responsible for making the gameserver high performance.
• By regular profilings I'm up to find bottlenecks in the current implementations and working together with the game developers to solve them. In addition to this incrementally optimizing the Garbage Collector and figuring out what combinations of JVM parameters meet our requirements of a mixture of consistent (not highest) throughput and GC cycles.
• At last I'd build the internal asynchronous framework for handling client-requests, enqueue and calculate them and queue the preserialized results in a native buffer cache until the client picks them up by Long-Polling.

Jul 2011 – Mar 2012 · 8 mos · Köln und Umgebung, Deutschland

• The internally used offer calculation and booking system was completely rewritten from scretch and business and technical requirements were defined in coorperation with the operating departments. In a team of more than 20 people I was working (with 4 other peoples) on the deep internals of the offering process and calculation of best price offers. In a the clusterized environment we implemented a fully distributed, highly fast process for these kinds of calculations. The implementation was based on an internally developed (Spring based) Service Layer architecture very similar to the Distributed OSGi environments where services are registered and consumed.

Jan 2008 – Jun 2011 · 3 yrs 5 mos · Solingen

• Building an online solution for recruitings and recruiting tests I was responsible for implementing additional test features and customer wishes to the recruiting test solution.
• The solutions were implemented as fully rich client HTML applications using ExtJS and JQuery.
• The backend stack included working with Spring Framework and Apache Tomcat as well as the database backend and for the persistence Apache Torque was used as the ORM layer.
• On the recruiting solution there was a Apache Karaf stack with static files provided by an Apache webserver.

Apr 2003 – Dec 2013 · 10 yrs 8 mos · Remscheid

• i-Style Design is my small all time company which is in term just a bigger hobby. In unregular intervals some interesting project arises which give some extra money and a lot of extra knowledge and experience.
• Over the last years there were a wide range of projects build starting with touchscreen playunits for children up to 10 years (build for a large fastfood company) and 2:1 meters sized Tetris like game using LED canvas and capacitive foot controlling unit, over backend implementation for an unfinished 3D shopping mall, to HTML streaming chatserver solutions.