Jan Kotek

I am a software developer and an amateur astronomer. I develop Java database engine MapDB (also known as JDBM4). I also contribute to number of open-source projects. I solve challenging tasks in unusual and innovative way. I am Czech and I live in Athens with my wife and little daughter.

Software Projects

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.


My Linkedin profile contains most recent info. Short version:

Now - Self-employed, mostly MapDB related work.

2012-2013 - Avaya
Realtime reporting, webservice integration.

2008-2012 - APC
Work on large multiplatform power management desktop application with million+ users.

2006-2008 - Duolog Technologies
Develop Eclipse based app for System-On-Chip design.

prior - accounting apps in Java, PHP web/wap development


I studied physics at MFF UK and Business Information Systems at VSE. I have bachelor's degree from IT.

Other stuff

I am keen skywatcher, I have largest telescope in county (except university ;-)). I made number of trips to La Palma and Attacama to see truly dark skies. I also like archery.