John Davies, TweetCTO and Founder of Incept5
Biography: John Davies
Sometimes you just know something should be running faster, but as long as it runs fast enough you leave it as-is. Then, a few clients start having interesting challenges and you realise you're going to need to start tuning the JVM to address the issues encountered. In this presentation, John will walk through two real-world performance tuning scenarios that he has encountered - topics to be covered include memory usage, object creation, I/O throttling, serialisation, benchmarking and testing. Although the majority of it is not rocket science, it can be astonishing how a few small changes can make a huge difference to the performance of a JVM application. When do you have to consider giving up object-oriented elegance in exchange for specific optimisations based on the way the JVM works? How much of an impact does object allocation have on a modern JVM? How good are developers at guessing where the real bottleneck is? Join us to learn the answers to these questions, and to gain insight into what's really involved in JVM tuning.
Presentation: TweetPractical Enterprise Integration
Some of the most expensive development tasks in large IT projects involve systems integration. Frequently these run over budget due to apparently simple concerns such as adherence to agreed messaging standards, which hide a large degree of complexity that often isn't fully apparent until the system moves into production. While there is no single 'right' way to address these challenges, there are approaches that are proven to reduce development time and increase operational reliability.
This session will showcase tried and tested patterns which have successfully delivered numerous systems integration projects and continue to keep them running as standards and systems evolve. You'll see how ESBs and frameworks such as Mule, Camel, Integration Objects & Spring Integration provide a foundation that scales to processing hundreds of thousands of messages per second with minimal latency and reduces the pain of regular updates to message formats.
Whether you're handling 10s of messages per day or 10s of millions of messages per hour, processing per-message or per-batch, handling binary SS7 telecommunications messages, EDIFACT messages for a retail client, FIX / SWIFT financial services messages or more universal XML & CSV, this session will help you regain control over your enterprise integration.
Presentation: TweetHard things made easy - Part 2
How to make your first (£€$) million
"Un-employable" John will cover some of the basics of being an entrepreneur in the IT world, creating a business from nothing and selling it for millions, do you have it in you?
From zero to a hello world app on the iPhone
RaspberryPi, Android, Mac, PC, you could probably write software for any of them but getting started on the iPhone has got to be one of the easiest and most rewarding. With several successful apps in the app store John is now trying to teach programming to his 3 young boys, if his 9 year old can do it so can you!
Mysteries of floating point computation
Why do floating point calculations work just fine sometimes and mysteriously fail at other times? Can you predict how much error to expect in floating point?
This talk will review the anatomy of floating point numbers, explain common problems with floating point calculations, and explain how to avoid these problems.