Jan Kotek 
I am a software developer and an amateur astronomer. I contribute to number of open-source projects. I solve challenging tasks in unusual and innovative way. I live in Galway (Ireland) with my wife and little daughter.
My public work can be found on Github. I mostly work on big-data and astronomy related stuff.
MapDB (former JDBM) is an innovative database engine written in Java. It has outstanding performance and very user-friendly API. Sometimes it is described as Redis for Java. In reality it is alternative memory management system for Java, its goal is to solve Heap limited scalability introduced by GC and memory limitations.
Kotlin Eclipse JDT is an attempt to integrate Kotlin compiler with Java Development Tools. Eclipse team is refusing any sort of collaboration with alternative languages. This makes it very hard to develop Eclipse based IDE for alternative JVM languages (Scala IDE team would tell you:-)). My approach is to patch JDT directly and 'glue together' JDT and Kotlin compiler. It involves refactoring and modifying 2 million lines of code. This was pioneered by Groovy IDE team and I am reusing most of their work.
HEALPix ranges is refactoring of existing astronomical spatial library to use memory efficient data-structures. Previous version was line-by-line port from Fortran to Java. I cleaned it a bit and introduced interval-tree compression. This reduced hardware requirements by several magnitudes and made high-resolution maps practically possible. My improvement has been ported to many software tools and is now widely used by professional astronomers.
Asterope is long-term project to develop desktop planetarium for amateur astronomers. Most of my open-source work is driven by this project (for example early MapDB version was developed for this app). This project involves number crunching, image processing, visualization etc.