Viktor Klang

Viktor Klang is the Deputy CTO at Lightbend —- problem solver, developer, prolific contributor to the Akka project, Akka Tech Lead Emeritus, member of the Reactive Streams Special Interest Group and contributor to the Scala Standard Library concurrency APIs. Known from places such as, but not limited to, the Internet.

Jaroslav Tulach

Jaroslav Tulach is the founder and initial architect of NetBeans, which is not just a well known IDE, but also the first modular desktop application framework written in Java. I have seen, made and helped to recover from many API design mistakes. Such experiences forced me to write a book titled “Practical API Design”. These days I am helping OracleLabs to design the API of Truffle which is the fastest virtual machine on the planet.

Andrei Pangin

Andrei Pangin leads the development of Odnoklassniki social network, specializing in distributed systems and high-loaded server development. He previously worked on the HotSpot JVM, which became his favorite topic and area of expertise. Andrei is fond of sharing knowledge about unfamiliar features of OpenJDK. He is also known as one of the top JVM answerers on Stack Overflow.

Geert Bevin

Geert Bevin is a programmer, musician, instrument designer, author, speaker and open-source contributor. He is the principle software engineer and co-designer of the LinnStrument, heads up software and iOS at Moog Music, created the SendMIDI and ReceiveMIDI tools, created Geco MIDI for gestural music and GameWAVE for gestural gaming, worked on the Eigenharp, pioneered and contributed to Gentoo Linux, created the innovative web framework RIFE, and spent more than 15 years doing scalability and bytecode manipulation in Java. Geert plays the guitar and actively studies new musical instruments. He composes, arranges, sings and performs solo as well as with his band Flytecase.

Kirk Pepperdine

Kirk works for Kodewerk as a consultant offering Java performance-related services and training. He has developed and tuned applications written in C/C++, Smalltalk, and a variety of other languages. Kirk has written many articles and spoken at several conferences on the subject of performance tuning. He helped evolve as a resource for performance tuning tips and information. Recently he founded jClarity which is focused on building better performance diagnostic tooling.

Volker Simonis

Volker Simonis works in the SAP JVM Technology group for more than 10 years. He is an OpenJDK contributor from the very beginning and helped the SAP JVM team engage in the OpenJDK project. Currently he’s the project lead of the OpenJDK PowerPC/AIX and s390x porting projects and
a JDK 8/9 reviewer. He also represents SAP in the Executive Committee of the Java Community Process

Tomasz Nurkiewicz

Tomasz spent half of his life on programming, for the last decade professionally in Java land. Loves back-end, tolerates JavaScript. Passionate about alternative JVM languages. Disappointed with the quality of software written these days (so often by himself!), hates long methods and hidden side effects. Interested in charting, data analysis and reporting. Believes that computers were invented so that developers can automate boring and repetitive tasks. Also their own. On a daily basis works in financial sector. Involved in open-source, DZone’s Most Valuable Blogger, used to be very active on StackOverflow. Author, trainer, conference speaker, technical reviewer, runner. Claims that code not tested automatically is not a feature but just a rumour. Wrote “Reactive Programming with RxJava” for O’Reilly. Works for Allegro.

Richard Warburton

Richard is a Software Engineer, Teacher, Author and Java Champion. He has written the book “Java 8 Lambdas” for O’Reilly and helps developers learn via and He’s worked as a developer in diverse areas including Low Latency Trading Systems, Statistical Analytics, Static Analysis, Compilers and Network Protocols. He is a leader in the London Java Community. Richard is also a well known conference speaker, having talked at Devoxx, Javazone, QCon SF, JavaOne, JFokus, Devoxx UK, Geecon, Oredev, JAX London, JEEConf, Codemotion Rome, JProfessionals and Voxxed Days Luxembourg. He obtained a PhD in Computer Science from The University of Warwick and enjoys living in London.

Nitsan Wakart

A coder/blogger/speaker with a pedantic passion for performance and concurrency. Long time Java developer (circa. 2000), recent work focused on trading systems, messaging systems and JVM performance (at Azul Systems). Currently consulting for various clients. Lead developer on JCTools, a lock free Java concurrency framework aimed at low latency applications and framework and an active contributor to other open source projects. JUG Organizer Cape Town, South Africa

Bert Jan Schrijver

Bert Jan is a software craftsman at JPoint in the Netherlands and CTO at OpenValue. His focus is on Java, Continuous Delivery and DevOps. He is User Group leader for NLJUG, the Dutch Java User Group and a JavaOne Rock Star speaker. He loves to share his experience by speaking at conferences, writing for the Dutch Java magazine and helping out Devoxx4Kids with teaching kids how to code.

Sander Mak

Sander crafts scalable software at Luminis Technologies. With more than a decade of experience on the JVM platform, he specializes in modular Java and JavaScript development. Additionally, data analysis and machine learning are part of his ever growing list of interests. Sander loves sharing knowledge, for example through his blog at He is currently writing ‘Java 9 Modularity’ for O’Reilly, expected release summer 2017. Furthermore he speaks regularly at international developer conferences, sharing his passion for Java, alternative JVM languages and related technologies.

Evgeny Borisov

Evgeny Borisov works as Big Data Technical Leader in NAYA Technologies, an Israeli company. Evgeny has been programming in Java since 2001. Since then he took part in a large number of Enterprise-projects. Having passed the way from a simple programmer to architect and tired of routine, he became a free artist. Currently, Eugene writes and conducts courses, seminars and workshops for different audiences.

Rabea Gransberger

Rabea studied computer science and got a diploma in 2008. She is co-leading the software development department and is working as a software engineer on various projects at MEKO-S. Her main focus is on keeping the code base clean and educating the team on how to write better code. Rabea is a well known speaker at conferences and user groups around the world. She started the Java user group Bremen in 2012 and is part of the organisation team ever since. Besides software development she likes to watch football games in the local Weserstadium.

Ray Tsang

Ray is a Developer Advocate for the Google Cloud Platform. Ray had extensive hands on cross-industry enterprise systems integration delivery and management experiences during his time at Accenture, managed full stack application development, DevOps, and ITOps. Ray specialized in middleware, big data, and PaaS products during his time at Red Hat while contributing to open source projects, such as Infinispan. Aside from technology, Ray enjoys traveling and adventures.

Sébastien Deleuze

Sébastien works at Pivotal as a Spring Framework and Reactor commiter. He mostly works on the upcoming Spring Framework 5 Reactive support, Spring MVC, and Spring + Kotlin integration. He is also part of Mix-IT conference staff crew.

Nikita Salnikov-Tarnovski

Co-founder of Plumbr, the memory leak detection product, where he now contributes as core developer. Besides his daily technical tasks he is an active blogger, JavaOne RockStar and frequent conference speaker (Devoxx, JavaOne SF/Russia, GeeCon, 33rd Degree, TopConf, JavaDay, GeekOut, Joker, Jazoon, JPoint etc).

Prior to founding Plumbr, Nikita was a Java EE developer and performance consultant in the Baltics, and has worked with tens of different Java EE applications over the years. In the last four years he specialized in troubleshooting and performance optimization.

Sven Ruppert

Sven Ruppert has been coding Java since 1996. He is a Developer Advocate for Vaadin based in Munich. In his free time he is regularly speaking at Conferences like JavaOne/Jfokus/Devoxx/JavaZone/JavaLand and many more and contributes to IT periodicals, as well as tech portals.

Roman Elizarov

Roman Elizarov is a professional software developer with more than 16 years of experience. He had started his career at Devexperts, where he designed and developed high-performance trading software for leading brokerage firms and market data delivery services that routinely handle millions of events per second. He is an expert in Java and JVM, particularly in real-time data processing, algorithms and performance optimizations for modern architectures.

Roman currently works on Kotlin language at JetBrains. Having worked on very large systems compromising many modules written in different languages, he has a dream of a single language that can be used to write all parts of a very large distributed system, to share and reuse data models and algorithms without friction. Kotlin with JVM and JS backends and upcoming native compiler is the ideal candidate to realize this dream.

In 2000 Roman had graduated from St. Petersburg ITMO. He now teaches a course on concurrent and distributed programming in ITMO. During his undergraduate study he participated at ACM International Collegiate Programming Contest (ICPC). Since 1997 and until now Roman serves as a Chief Judge of Northeastern European Regional Programming Contest (NEERC) of ACM ICPC.

Richard North

Richard North is a principal engineer at SkyScanner in London, where he works in developer enablement. Prior to this he worked as a senior engineer in a consulting firm, working in implementation projects across a range of industries in the UK and Japan. His current focus is server-side development in Java and NodeJS, but he also enjoys iOS development and infrastructure automation. He created the TestContainers open source testing library in 2015, and continues to maintain it with support from ZeroTurnaround and other members of the community.

Mike Tunnicliffe

Mike Tunnicliffe is a member of the IBM Runtime Technology Center team at the Hursley Park Development Lab in the United Kingdom. He is a software engineer working on the development of runtime environments and associated tools and libraries. He spent many years troubleshooting customer problems on the IBM Java SDK. He has also contributed to Node.js, V8, Express and appmetrics. Recently he has shifted focus to Swift and the Kitura web framework.