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On Wednesday 9th May, we’re running an evening of presentations and live demos, all focused on Reactive Microservices with Micronaut and Open Cloud-Native Java. In our first talk, Graham Charters will give a presentation and live demonstration of how the MicroProfile initiative helps you build cloud-native Java microservices on open source, open standard APIs and, avoid lock-in to a single company. Then, Alvaro Sanchez-Mariscal will be discussing Reactive Microservices with Micronaut.

In preparation for the event we caught up with Graham and Alvaro. An IBM Senior Technical Staff Member and WebSphere Applications Server Developer Advocacy Lead, Graham takes a keen interest in emerging technologies and practices, and in particular programming models. His past exploits include establishing and contributing to open source projects at PHP and Apache; and participation in, and leading, industry standards at OASIS and the OSGi Alliance.

Alvaro Sanchez-Mariscal is a passionate developer and agile enthusiast with over 18 years’ experience. He now works as a Software Engineer at Object Computing (OCI), the company leading Groovy, Grails and Micronaut open-source development. Before working at OCI, Álvaro gained a wealth of experience across various industries and businesses; from gambling games to fintech, founding his own company, and working at organisations such as IBM BCS, BEA Systems and Sun Microsystems. Álvaro is also a speaker at conferences including GeeCON, JavaLand, JavaZone and Codemotion. You can find him on Twitter @alvaro_sanchez They gave us a summary of their ambitions for the event, the latest technology and words of wisdom for junior programmers.

1. Who do you think should come along?

GC – This talk should be of interest to Java Developers and Architects looking to develop, deploy and manage modern cloud-native Java microservices. The technologies the talk will focus on are the result of broad industry vendor and user collaboration. They also benefit from having multiple implementations, which means broader input to the design, and greater choice for users.

ASM- Micronaut is a brand new framework for the JVM, so we don’t expect any prior knowledge. Any Java developer is welcome!

2. What do you think are the three most interesting questions that this event will answer?

GC – The first question this talk will answer is, what is cloud-native, how did we get there, and what to look for in an environment to help me? Okay, maybe that’s three questions in one. Understanding how the industry evolved to cloud-native and the characteristics is an important foundation to choosing the right technologies and increasing the chances of success when embarking on a cloud-native journey.

The second question this talk will answer is, what is MicroProfile and how does it help me address the challenges of cloud-native? Based on the understanding established in answering the first question, this talk will introduce the MicroProfile technologies and, along with the use of demos, show how each helps in the development and management of cloud-native applications.

The third question this talk will answer, and some (ok, not many) would say the most important, is whether or not cloud-native should be hyphenated.

ASM – As we are introducing a new technology, the session will give the audience an idea of what Micronaut is and how can they use it in their projects.

They will also learn about Micronaut features that are similar to the ones in other frameworks like Spring and Grails. They should feel at home with Micronaut. Finally, attendees should understand that by using Micronaut they get the best of two worlds: the developer experience and productivity of frameworks like Spring Boot or Grails, and the performance of a compile-time reactive framework based on Netty.

3. Why do you think this presentation is important for people?

GC – As an industry we’ve made huge advances in how we deliver solutions, for example through Agile, DevOps Cloud and Microservices. These advances are the cornerstones of cloud-native. What is sometimes not immediately clear, is what this means in terms of the resulting impacts on how we develop, deploy and manage these modern cloud-native applications. This presentation will help people gain an appreciation of the new challenges and offer open technology choices for how to address them.

ASM – Micronaut was first announced in February and is still not yet public. We are still polishing some things before the first public milestone, which will be published in a matter of weeks. This is a unique opportunity to learn about it!

4. Any advice for junior programmers entering the industry?

GC – My advice to junior programmers entering the industry would be to not be afraid to ask questions; take every opportunity to learn something new. A strong technical foundation will stand you in good stead for the future. Lastly, understand what you enjoy and what motivates you and don’t lose sight of that as you seek to progress your career. If programming is what gives you the buzz, be the best programmer you can be.

ASM – The JVM ecosystem is quite crowded with excellent frameworks and sometimes the number of options are overwhelming. In my opinion, what makes the difference between a good developer and a great one is the ability to judge which technology is the best choice to solve a particular problem. To get this skill they should constantly learn about new technologies. Meetups like this at the LJC are a very convenient way to learn.

Reactive Microservices with Micronaut & Open Cloud-Native Java is happening on 9th May, 18:00 – 21:00 at IBM UK, SE1 9PZ. If you’d like to join us, please register here:


If you don’t already know, jPrime’s 4th conference at Sofia Tech Park, Bulgaria is coming up in less than a month (29th and 30th May). For those who are new to jPrime, it’s a conference focused on Java, various languages on the JVM, mobile, web and best practices. It’s run by the Bulgarian Java User Group and backed by some major businesses. Visitors have the opportunity to listen to some of the best international speakers, as well as presenters from Bulgaria and the Balkans. It’s not all work though… there’s also plenty of time for hacking, networking and fun.

In case you can’t tell, we’re a tad excited about jPrime. Ahead of the event we caught up with one of the organisers Ivan St Ivanov who gave us the lowdown on all things jPrime.

Ivan is the Co-Founder and Senior Programmer at VIDA Software, he also does a variety of consultancy roles, teaches Java and Microservices courses, is an active JUG member and is studying for a PhD in the field of Cloud Multi-Tenancy… we’re seriously impressed.

Here’s what we learnt:

  • jPrime is organised by a group of true enthusiasts – all profits go back into the next year’s JUG events, the organisers do it for the love of it.
  • Now in its 4th year, the conference has grown into a 2-day event with over 700 attendees.
  • The organisers come with a massive range of interests and areas of expertise. There are those that are most interested in the current hype (e.g. hmm, Kotlin, Spring 5 + Reactor, Blockchain); there are also people (Ivan being one of them) that are evangelical about the MicroProfile, and another lead who is active in the OSGi community.
  • There’s a jam-packed agenda, far too many to list, but safe to say, all things Java, languages on the JVM, mobile, web and best practices are explored by some excellent speakers.

And if that’s not enough…

  • The weather in Sofia around jPrime is typically beautiful so it’s a great opportunity to get out and explore the beautiful capital of Bulgaria. It has a long ancient history, so there’s plenty to see outside of the conference.

We managed to get our hands on some tickets for jPrime, and in the spirit of sharing the love we’d like to give them away. If you’d like to be in with a chance of winning a ticket to this year’s conference, you can enter the raffle here – You can see all the details, including the agenda for jPrime here: and you can find Ivan on Twitter at @ivan_stefanov

On Tuesday 8th May, we’re running an event focused on Java 9 and Java 10. We’ll review their features in three parts: improvements, additions, and advances; specifically, we’ll look at improvements and additions to the language that are not only exciting, but also useful for everyday programming. We’ll be using live coding to illustrate the concepts and their benefits.


We’re really pleased to be joined at the event by Dr. Venkat Subramaniam. Venkat is, amongst other accolades, an award-winning Author; Founder of Agile Developer, Inc.; Creator of; and an instructional Professor at the University of Houston. He has trained and mentored thousands of Software Developers in the US, Canada, Europe, and Asia, and is regularly invited to speak at international conferences. Venkat’s overarching aim is to help his client’s software projects to succeed through the use of sustainable agile practices.

In preparation for the event we had a chat with Venkat and got his view on the session, the latest technologies and advice for aspiring programmers.

1. Why do you think this presentation is important for people?

A lot of the focus on Java 9 has been around Modules. That’s important, but there are a number of other interesting and useful aspects to Java 9 and 10 as well; learning about these can help us with the design and implementation of code in modern Java.

2. Who do you think should come along?

Bring along a friend, a colleague, a relative, a child – just about anyone who would benefit from meeting other Developers. If you’re a Programmer, Lead Developer or Architect on any projects that use Java, and you’re curious about the more recent features of the language, this presentation is for you.

3. What Java/JVM technologies are interesting you most at the moment?

Quite a few, but I’ll mention just one here. I’m really excited about where Reactive programming is heading.

4. Any advice for junior programmers entering the industry?

A professional who doesn’t learn to fail, fails to learn. Ask your colleagues to critique your work and improve based on the feedback they provide. Regularly attend user group events. It is never too early to get involved in the community.

Java 9 and Java 10: The Key Parts, is happening on 8th May, 18:00 – 21:00 . If you’d like to join us, please register here:

Venkat is a (co)author of multiple technical books, including the 2007 Jolt Productivity award winning book ‘Practices of an Agile Developer’. You can find a list of his books at You can also reach him by email at or on twitter at @venkat_s.

The first in a series of interactive sessions discussing the state of garbage collection in 2018 takes place on May 1st. Experts including Martijn Verburg, Richard Warburton and John Oliver will be taking part, sharing their knowledge on all things garbage collection related. We spoke to Martijn and Richard to get their take on the event.

1. Who do you think should come along?

MW: Any Java developers (or developers who write code on the JVM) who care about how their code performs on the JVM, especially in small (e.g. uService apps) or large (e.g. Big Data style apps)
RW: Java developers who have a solid grasp of the basic language and tool chain and want to understand more about how the JVM works under the hood and how to make better use of the garbage collection subsystem.

2. What is your background in GC?

MW: I’m the CEO of jClarity, a tooling company that specialises in GC analysis. I have a decent understanding of GC algorithms and performance tuning, but certainly not at the level of the world’s experts (some of who are in jClarity’s engineering team)!
RW: I’ve worked previously (and currently) for JVM tool vendors who wrote tooling around GC logs and understanding GC. I’ve also done bespoke development and consulting work on problems that have low latency requirements and thus have an interaction with GC tooling.

3. Why do you think it’s such an important topic to get right?

MW: When Java Garbage collects it often has a Stop the World (STW) phase, which brings the whole JVM to a stop, this can greatly impact end user / system experience depending on how often those pauses occur and how long each pause occurs for.
RW: Performance is a big driver of business value. To put it simply happy customers are a great thing to have and customers aren’t happy when their website is unresponsive. It can also be a strong driver of business value in spaces such as AdTech or HFT where low latency really matters.

4. What do you think are the three most interesting questions that this event will answer?

1) What has changed in Java 9+ with regards to GC behaviour?
2) What’s the future direction of GC in Java?
3) How do I tune GC for my small container based uService apps?
1) How do I know when I have a GC problem?
2) What is changing around GC in future Java versions?
3) How do I understand when to look at GC rather than other application problems.

5. Any advice for junior programmers entering the industry?

MW: Whatever they tell you, it’s a people problem! So even with a technical event like a GC Panel, there’s always a strong human element. How does GC impact people, what performance characteristics do people care about? How do we help people tune etc?
RW: Have fun.

The Garbage Collection 2018 event promises to be an interesting and informative evening, so come along and see what you can learn. It’s a great opportunity to join in with an analysis of changes in Java 9, tuning your application, extracting information out of the JVM, tooling to aid interpretation, and looking at and beyond OpenJDK/Oracle JDK.
You’ll also be able to find out about the best sources of garbage collection information and where to find them.

If you are involved with garbage collection in any capacity within your organization, or you just have an interest in the topic, this is a chance to increase your understanding and advance your knowledge.

If you’re interested, then sign up to reserve your place:, and join the Slack Group at

On Wednesday 2nd May, we’re running an event all about Microservices and Serverless. Specifically, we’ll be thinking about: how we got here, things to think about and let’s see you do it.

We’ll be joined at the event by Tim Graves, a Cloud Native Solutions Specialist at Oracle. This job title sounds grand, but as you may have guessed, it means he helps people to solve their problems using cloud-based solutions. Prior to his current job, Tim has held many other roles, including but not limited to… Pre-Sales, Product Management, Requirements Engineering and Architect; he also has experience in a variety of product areas…Security, Storage and IOT. When he’s not hard at work Tim is a keen skier and unprofessional chef.

Tim Graves headshot

In preparation for the event we had a chat with Tim and got his view on the session, the latest technologies and advice for up and coming programmers.

1. Why do you think this presentation is important for people?

Serverless is the latest architecture on the “Hype Curve” (You should have seen how often it was mentioned at the O’Reilly software architecture conference last winter.) In this talk we’re going to look a little about the history of how we got to serverless, and also things you should consider when the dream of the hype runs headlong into the concrete wall of reality.

2. Who do you think should come along?

The event is suitable for programmers and non-programmers who are interested in Microservices and Serverless and in particular, open source serverless frameworks.

3. What Java/JVM technologies are interesting you most at the moment?

I’m currently spending *way* more time using Streams and Lambdas than I ever expected I would; if you’re not familiar with them go find out more.

4. Any advice for junior programmers entering the industry?

Learn about how to do Architecture, not just Programming, in the short term it’ll help you understand how your work fits into the overall picture, and in the longer term it opens up many more opportunities

The Microservices and Serverless event is happening on 2nd May, 18:00 – 20:00 at WeWork Waterhouse Square, EC1N 2SW. If you’d like to join us, please register here:

UP NEXT_idea

The LJC has a history of encouraging, mentoring and developing new speakers. Many speakers on the international conference circuit gave their first presentations at LJC events, or the annual LJC unconference. Last year the LJC teamed up with Devoxx UK and RecWorks/Meet a Mentor to take these values and create an ongoing initiative around them. This initiative is known as “Up Next”.

To date we’ve run three “Up Next” events. We kicked things off in December, with a session designed to encourage and mentor new speakers; this was followed by an event with two new speakers; and finally an event in association with IBM, where a number of junior speakers practised their skills and received a recording of their presentations.

I am *extremely* proud to say that initiative has already lead to two new speakers being accepted to speak at this year’s Devoxx UK conference. This is huge – I’m so pleased.

One of the main aims of Up Next is to achieve greater diversity of speakers within the LJC, and at London conferences. No doubt you’ve seen the stories about conferences, panels and events that lack a diverse range of speakers. In many situations organisers have gone to great lengths to achieve diversity but haven’t been successful. As well as the fact that we all know diversity is great for many reasons, lack of diversity can also lead to sponsorship being pulled, and conferences being cancelled.  Clearly the industry has a problem and the easiest solution that we can see, is to flood the market with a diverse new generation of speakers.

So, the Up Next initiative is a proven solution (on a small scale). To keep the momentum, we now need more speaker-mentors to see if we can prove it at scale. If you’re an experienced speaker (meetups or conferences) then please get in touch. There are a number of ways you can help out that won’t require much of your time. If you are in any way interested in helping develop the next generation of speakers, then please please let me know.

On Tuesday 24th April our colleagues at Docklands.LJC welcome Steve Wallin, Programme Director of IBM Runtime Technologies, who will be discussing Eclipse OpenJ9 – driving JVM innovation for Cloud Native Applications.

Steve Wallin profile

In anticipation of the event, we caught up with Steve for a quick-fire interview to get his thoughts on the session, the latest Java technologies and his advice for new programmers.

Why do you think this presentation is important for people?
JVM innovation is a hot topic right now! With Hotspot and Graal from Oracle, Falcon from Azul and now IBM open sourcing J9 at Eclipse there is real choice in finding the right JVM for your application requirements.

How do you ensure you are getting the most out of your hardware infrastructure and that your application is performing at its best?
There are a breadth of performance characteristics like application memory footprint, GC pause time, predictability/repeatability, ramp-up, peak throughput that all need to be carefully balanced by the JVM to provide the most efficient use of system resources. The whole model for the dynamics around these characteristics needs to change to include workloads designed for cloud and container deployment.

This talk will cover some of the new challenges which cloud and container scenarios create, what Eclipse OpenJ9 can already do to help and in which areas we are focused driving innovation going forward.

Would it be cool to reduce your memory footprint by 60% and improve startup by 40% simply by changing a couple of lines in your Dockerfile ?
Come and see the demo !

I’ll also make it interactive and you will get a chance to ask me anything you like.

What Java/JVM technologies are interesting you most at the moment?
It is great that there’s a renewed focus on language syntax , native interop and the removal of templating and generally minimizing the volume of code required for a developer to write to get the job done. Amber, Panama and Valhalla are all key projects at OpenJDK that will drive important features into the language over the next few years and will make the code easier to write, better to debug and enable cross language integration that JNI has not really been able to provide effectively.

In this session I will be focusing more on my interests in containerised applications, and how, with Docker kubernetes deployments we need to drive down the memory footprint and improve start-up performance to have Java competitive for microservices and cloud functions when compared to other technology options.

There are also broader challenges in the Java ecosystem for developers related to the new release cadence and migration challenges beyond Java 8. This tension between agility, time to value and stability are provoking some interesting discussions. I’m really pleased to have a team working with the LJC and a broad range of community members at AdoptOpenJDK ( which is helping to mitigate some of these challenges.

Finally do you have any advice for junior programmers entering the industry?
As a software developer and leader of software engineering teams for over 20 years there have been a huge number of ‘next big things’in the technology landscape where I have worked. As a junior developer understand your depth and breadth of skills and focus on finding your passion. If you are having fun and enjoying what you do then you’ll likely do your best work.

I do believe that the best programmers have an ability to keep up with the trends, but more importantly they understand how to use the softer skills to work with others, collaborate, lead, empathise with users and understand the motivations of those around them.
If you are able to continue to improve your personal, communication and presentation skills at the same pace as the technical skills then this puts you in a much better position to build better outcomes for your clients.

If you’d like to join us at the event, please register at:


On Tuesday 24th April we’re running an event in association with Microsoft: Live Coding with Spring Music. At the event we’ll be joined by Brian Benz, a Senior Cloud Developer Advocate at Microsoft. In his role, Brian helps Java developers to get the most out of Azure. Before joining Microsoft, Brian was a Solution Architect, Consultant, Developer, Author and Presenter at IBM and Deloitte amongst others.

Headshot 2015

In anticipation of the event, we caught up with Brian for a quick-fire interview to get his thoughts on the session, the latest Java technologies and his advice for new programmers.

Why do you think this presentation is important for people?

I’ll show people how to deploy and run Java applications in the cloud, using command line and open source tools you can get for free.  Free is good, and the cloud is powerful.  That’s a good combination!

Who do you think should come along?

Anyone interested in the latest tips, tricks and tools for Java developers.  And people who like swag, food and drinks, Microsoft and the LJC are buying!

What Java/JVM technologies are interesting you most at the moment? 

Cloud Native Java apps using Spring are most interesting to me these days.  Also, the related technologies that are interesting now, accessible by Java apps, like ML, AI, IoT, to expand the possibilities in today’s Java apps.

Any advice for junior programmers entering the industry?

You have it so good!  Cheapish hardware, meetups, stack overflow, cheap servers and services in the cloud.  Get started and find your way, the world is your command line.

The Live Coding with Spring Music session is happening at 18:15 on 24th April at Runway East Moorgate, 10 Finsbury Square, EC2A 1AF. If you’d like to join us, please register here:

You can also follow Brian on Twitter @bbenz.

Steve Poole

This is an interview with seasoned public speaker, IBM’s Steve Poole. Steve had a vision of creating a completely new kind of event as part of our Up Next initiative to mentor aspiring developers. The event titled “Find your Java voice” is happening in the evening of April 11th at IBM Southbank. You can RSVP here if you haven’t already:

We spoke to Steve and asked him questions about his vision for the event and why he feels getting involved in presenting is a great idea for developers.

Can you give us a tl;dr overview of the event and what is going to happen?

This event is designed to help give new speakers the chance to improve their presentation skills and gain a professional video of themselves speaking. We know how hard it can be for people to get a talk accepted at a conference. By having a video of themselves speaking it will help with conference selection committees who are looking for proof of presentation skills.

We’ll give every new speaker the chance to speak, be professionally filmed and receive feedback from our mentors. Since it doesn’t make sense to film the speaker before the advice we’ll give everyone the chance to speak first, get some feedback and then talk again later in the event where the will be filmed by IBM’s film crew.

Each new speaker has to come with a talk prepared. That’s not as scary as it sounds. We’re looking for a 5 minute talk (sometimes called a Lightning Talk) on any subject that has something to do with computers. No slides are needed (though not forbidden). Our main advice is to talk about what you know well. Whether it’s your experiences in installing Windows 10, what you think about <insert tech here>, how you wrote a really fast sort when you were 10 – The topic is not important. The important part is that it is a subject you know well.

The mentors will all be experienced speakers and will have many (and likely differing) opinions about speaking.

What are you hoping to achieve in this event?

That’s simple: help developers improve their career by gaining some vital speaking experience in a friendly but real life environment. I want our volunteer speakers to leave the event having had some fun, gained some useful advise and with a professionally produced video of them speaking.

Why do you think people should get involved as speakers?

Public speaking helps you with a few things. It certainly improves your confidence. Public speaking is often rated as a high stress activity but the reality is that it’s not actually that bad (trust me). People often think that they need to be the greatest ever expert on a topic before they could stand up and talk about it. That’s an incorrect view too. I would never claim to be ‘the’ expert. All my talks are through the lens of my experience. If I’m new to something I’ll share what I’ve learnt – as a newbie! So public speaking indirectly helps you throw off some of that ‘impostor syndrome’ that can hold you back.

Public speaking is generally good for your career. Personal visibility helps when looking for new opportunities and your talks will show others what you know.

Speaking also helps your communications skills across the board. The act of creating a presentation will teach you important aspects of presenting ideas and information to others. The confidence and personal insight you can get from speaking will helps you generally when dealing with other people in your life – whether difficult executives, or annoying cold callers, once you’ve spoken in front of an audience they will become easier to deal with.

Why do you think it’s important that junior speakers connect with mentors?

Having a mentor (at any stage of your life or career) helps you see things differently. It’s often easy to think you understand how the world works. With a single viewpoint you’re limited to using your single experience to predict and understand what you see. That can often lead to unfortunate under or over estimating the scale of new challenges. Having a mentor will help you get a different perspective and give you valuable insights. For this event I hope that the mentors present will help remove the mystique of public speaking and show that it’s not as scary as some believe.

Who would you recommend comes to the event?

We want three groups of people.

Firstly new (or nearly new) speakers. If you’ve willing to try standing in front of an audience for the first time or you’ve spoken at a conference once and want more help with your presentation skills this is the event for you.
Secondly we want seasoned mentors. You know who you are. Come along and pay forward the help that you got when learning how to be a public speaker.
Finally, and by no means last, we want an audience who will provide that realistic and positive experience for our new speakers.

Find your Java voice is happening in the evening of April 11th at IBM Southbank. You can RSVP here: You can also follow Steve Poole on twitter: @spoole167


UP NEXT_idea

Hi guys,

My name is Maggie Cranford and I’m a professional writer currently working with RecWorks, strengthening and developing tech communities in and around London.

I hope you enjoyed a break this summer.  We’re well into September already, and a new season of talks, meet-ups and workshops is getting underway in and around London.
Whether you are looking for details of regular sessions where you can get together with like-minded people, or sessions focused on more specific topics such as learning Apache Cassandra or tools and techniques to improve coding, all the contact details and information you need are given below.
Please do let us know which events you find particularly useful, as this will help the organisers of events in the future.

Monday 15th September
Evening Code and Coffee / Craft Beer
Every fortnight, we meet for coffee, code, craft beer, and some great food.
This is a great opportunity to:
• meet other cool software craftsmen
• work on pet or open source projects
• pair with someone else on whatever you like (katas, koans, etc)
• ask someone to join or help you with your own project
• have a face-to-face meeting with your mentor or mentee
• have a nice chat over coffee and beer
We’ll be meeting in “Look mum no hands!”, a laptop friendly cafe/bar that’s open until 10pm, and sells great coffee, excellent beers, and some tasty food. They also repair bikes and hang them from the ceiling like chandeliers, because why not?
London Software Craftsman Community

Monday 15th September
7 languages in 7 weeks: Clojure day 1
A workshop run in the Code Dojo format for people reading and working through the Pragmatic Programmers book “Seven Languages in Seven Weeks” by Bruce Tate. This time, we’ll be starting Clojure.
London Code Dojo

Wednesday 17th September
“Leaning on the two Ts” Mani Sarkar, & “Tests need love too” Colin Vipurs
Talk 1 – Leaning on Tools & Techniques to Improve Code Quality – Presented by Mani Sarkar (45 mins approx.)
Attendees of this talk will learn about my experience when learning to use static analysis tools (i.e. SonarQube) and some of its features. In addition also find out how it can be used to improve your code quality and personal practice. A number of tools will also be mentioned and how to include them in your practise.
Talk 2 – “Tests Need Love Too: Common Reasons Unit Tests Are Brittle” – Presented by Colin Vipurs (45 mins approx)
Any developer who cares about software quality should be committed to writing unit tests. Used well it can be a vital tool in every developer’s toolbox, but unfortunately the theory and practice don’t always match up. Easily-made mistakes can lead to brittle, unmaintainable and ‘write-only’ tests that not only become difficult to work on, but can lead to a hatred of unit testing in general. Presented here are examples of these mistakes with code samples, why you’re making them and how to avoid them in future.
London Java Community

Wednesday 17th September
1: Couchbase and Hadoop. 2: Sub-millisecond response times with Couchbase.
We needed a bridge between the real-time tier, where we used Couchbase, and the batch tier, built on Hadoop. When we couldn’t find a suitable option, we built our own: Couchdoop – an open-source Hadoop connector for Couchbase.
Based on our experience with Couchdoop, we will discuss best practices in creating connectors for Hadoop and NoSQL DBs. We’ll address the challenges we encountered while developing Couchdoop and share how we tuned it for performance.
Together with Bigstep, we will also show how much throughput that can be squeezed from a Hadoop connector. We have benchmarked Couchdoop for performance and we’ll talk about the behavior you can expect and tweaks that can improve the performance of your big data setup.

Thursday 18th September
Scala Coding Dojo
A regular coding dojo session run on every third Thursday of the month. The dojo is now held regularly at the central London offices of Springer.
London Scala Users’ Group

Thursday 18th September
HTML5, AngularJS, Groovy, Java and MongoDB all together – what could go wrong?
It seems to have been a common theme amongst startups to create the MVP (Minimum Viable Product) in a language that facilitates rapid prototyping (for example Ruby), and then migrate to the JVM when the application has proved itself and requires more in terms of stability and performance..
Virtual Java User Group

Monday 22nd September
Couchbase Server developer day
The ideal opportunity for developers to get their first taste of the Couchbase Server NoSQL document database.
In this hands-on session we’ll cover:
Couchbase concepts and architecture.
First steps with the Couchbase Java SDK.
Building a first simple Java app using Couchbase.
Querying data with Couchbase.
Introduction to data modelling with Couchbase.
Introduction to Couchbase Mobile.
All you need to bring is your laptop with your favourite Java IDE installed.
Lunch is provided.
We expect this event to fill up quickly so please note that we can offer access only to people who register using this Eventbrite event.

Monday 22nd September
Hazelcast introduction
David Brimley, Solutions Engineer at Hazlecast, will come give an introduction to the Hazlecast open source in-memory data grid.
Hazelcast will also be kindly providing pizza and drinks.
London NoSQL

Tuesday 23rd September
Michael Donaghy: Stacking Monads High
Scala’s rich type system makes it easy to include composable effects as part of a method’s type. Monads like Validation, Future, and Reader give us explicit control over when these effects happen; stacked monad transformers mean we can track several different kinds of effects without sacrificing code reuse. But if we try to control every effect we can quickly wind up wondering how we call our UserName => Reader[ApplicationContext, UserProfile] with an EitherT[({type L[A]=ReaderT[ApplicationContext, Future, A]})#L, NonEmptyList[NetworkError], UserName]. This talk looks at ways to keep monad stacks clear and concise.
London Scala Users’ Group

Thursday 2nd October
Apache Cassandra for Java Developers – Why, What & How – Johnny Miller
Java developers interested in learning about Apache Cassandra and how to use it. Attendees will be introduced to some of its most popular use cases and given an architectural overview of Cassandra. They will also be show how to model their data on Cassandra and how to use the Java driver.
London Java Community

Saturday 4th October
Architect Camp 5
Good architects Practice, Practice, Practice. A whole day architecting a system. Interview, Design, Validate. 30 people 6 teams, one objective… to become better at our craft. Java, .Net python….who cares… all welcome, just leave your ego’s at the door.
Software Architect & Mentorship Group

Wednesday 1st October
Meet A Mentor – University College London
**Undergraduates/Graduates only** Have you always wondered what you want to do when you graduate?
Are you worried about all the talk of grads finding it hard to find work and what it will mean for you?
Do you want to know the difference between working in a bank, a gaming company or a startup?
What technology should you specialise in? Java, Ruby or any of the other countless programming languages?
Now is the chance to find out. You may well have heard the buzz about the Meet a Mentor events – this is the next in a series of events open to all students.
Graduate Developer Community

Thursday 2nd October
London Platform as a Service – Heroku: time for a fresh look
Get a developer’s point of view on deploying your code without spending weeks learning DevOps tools. If you already know Git*, you know how to use Heroku. There are a lot of new things to see, from a new dashboard in Node.js to a new stack based on Ubuntu 14.04. We’ll cover the basics of how Heroku works underneath and the different levels of compute resources you can select (P1, P2 and PX dynos).
We will round off with some fun with Heroku Button, enabling anyone to deploy your app from your public Git repo to their own Heroku account at the press of a button!
* If you don’t know Git yet, we’ll be happy to show you how.
The London PaaS User Group (LOPUG)

That’s everything for now. If you’re interested in getting your group or event on the list then please let us know – bc

Until next time,



What is the LJC

The London Java Community (LJC) is a group of Java Enthusiasts who are interested in benefiting from shared knowledge in the industry. Through our forum and regular meetings you can keep in touch with the latest industry developments, learn new Java (& other JVM) technologies, meet other developers, discuss technical/non technical issues and network further throughout the Java Community.