The London Java Community for the Docklands

Jul 14 2015

Inaugral Docklands.LJC event – Stephen Colebourne and Simon Maple

2015, open gamma, profiler, simon maple, stephen colebourne

We are pleased to bring you news of the inaugural event of the Docklands.LJC: a group within the main London Java Community that will be focusing on the developer community in and around Docklands, with the Twitter tag #dljcjug

The Docklands.LJC will meet on the second Tuesday of each month. At this opening event we are delighted to have two excellent speakers coming to talk:

Stephen Colebourne - OpenGamma, a modern Java 8 based open-source toolkit for market risk

An Open Source toolkit for market risk? Yes! OpenGamma provides open source software for market risk, as a leading provider of OTC market structure solutions.

This talk will cover our soon-to-be-released next-generation toolkit, engineered for ease of use and performance. Written in Java 8, it provides key components for market risk application development, from time-series and schedules to market data and reporting, for a range of asset classes.

Come along to this talk to learn more about OpenGamma, how we build our software, and how we make best use of Java 8 in a modern software stack.

Simon Maple - Is your profiler speaking the same language as you?

Profilers are absolute beasts. And profilers might prove useful to pinpoint the performance issues in your Java applications.

By using profilers, developers are fortunate to find the root cause of an issue at hand. However, it requires effort to actually comprehend the data collected by the profiler. Due to the inherent complexity of the data, one has to understand how this data is collected. And thus understand how the profiler actually works.

During this talk we will go through the classic profiler features. What is a hotspot? What is the difference between sampling and instrumentation from the profiler point of view? What are the problems with either of those methods? What is the time budget of the application? And more!

I will also showcase a new kid on the block among the profiling tools: XRebel. This tool provides insight into application behaviour and permits the developers to discover application level issues.

The presentation and video recorded from the event are available at InfoQ.


Stephen Colebourne is Engineering Lead, Platform at OpenGamma. Prior to OpenGamma, Stephen worked at Sun Alliance insurance and airline IT co-operative SITA. He is best known for his work in open source and his blog. He played a major part in Apache Commons Lang, Collections and IO leading to membership of the Apache Software Foundation. He also created Joda-Time which was refined via JSR-310 to form the java.time API in Java SE 8. He contributes to debates on the future of Java, including proposals for the diamond operator for generics and FCM closures, both of which are close to the adopted changes in Java 7 and 8. Stephen is a frequent conference speaker, JavaOne Rock Star and Java Champion.

Simon Maple is a Developer Advocate at ZeroTurnaround, and is all about community discussion and interaction. His passion around technical communities led him to become the founder and organiser of the vJUG (virtualJUG), as well as continuing to be an active leader of the London Java Community (LJC). Simon’s energy in building and driving the Java community forward culminated in him becoming a Java Champion in 2014. Previously, Simon worked for IBM for almost 12 years, testing, developing and evangelising WebSphere Application Server. He is an experienced speaker, having presented at JavaOne, DevoxxUK, DevoxxFR, IBM Impact, JDC, JMaghreb and many more (including the vJUG :), and is a keen technical writer for RebelLabs.

This event is being hosted by Credit Suisse at London. The sign-up for the event is hosted at