What we’re about
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.
FAQ
What is the LJC?
What goes on in the LJC?
Who can join?
Is there a fee to Join, is there a fee for the events?
How do I join?
Do you have to go to every presentation?
Where are the events held?
Can I read some member feedback?
Can I give a presentation to the LJC?
What is the LJC?
The LJC is an official Java User Group for developers based in London. It was founded in November 2007 and since then has grown to over 5000 members and is now the biggest Java User Group in the UK.
What goes on in the LJC?
We run a variety of regular events ranging from social events and technical presentations to our full day unconference. On top of the events we run prize draws and have an active mailing list/forum. We support the Graduate Development Community in London and promote London based Open Source Software projects where possible.
Who can join?
Membership is restricted to Java developers working in or around London (or those hoping to train in Java, or relocate to London). Membership will not be granted to those involved in the recruitment industry.
Is there a fee to Join, is there a fee for the events?
It’s completely free to join and 99% of our events are completely free. The only event which is charged for is the Unconference, the charge is minimal and it is there to cover refreshments on the day.
How do I join?
Just click on the link on this page to sign up to the mailing list, you'll hear of all of our latest news and events and can take part in the monthly prize draws.
Do you have to go to every presentation?
Absolutely not – it’s completely up to you which events you attend and which you don’t. Every event attracts a different crowd.
Where are the events held?
Europe's Premier technical training company, Skills Matter (Barbican) sponsor most of our events by providing the venue.
Can I read some member feedback?
We have been collecting feedback for the last few years from our members you can read it here: https://www.meetup.com/Londonjavacommunity/about/comments/?op=all
Can I give a presentation to the LJC?
We run various in-person and online events, and welcome highly experienced speakers, all the way through to those just starting out. If you have a presentation you'd like to submit for consideration, please visit https://sessionize.com/ljc
For further information see our blog here: https://londonjavacommunity.wordpress.com/s... Do not hesitate to get in touch with any questions.
Barry Cranford
Founder of London Java Community
Upcoming events (2)
See all- LJC Meet-up at LMAXLMAX HQ, London
Please register on Eventbrite to join this event.
About this event
The LJC is delighted to be partnering with our sponsor LMAX for an exciting new meetup.
This will be a wonderful opportunity to learn, network and enjoy beer and pizza together.
Huge thanks to our friends at LMAX for sponsoring this event and supporting our CommunitySpeaker One:
Miguel Trigueira is a Software Engineer who is open to work
Talk: Java 25 LTS for Low Latency : A Whirlwind TourBetween the last Java LTS (21) and 25n(which is scheduled to be out on 16 September 2025), there have been many changes that could be relevant to low latency systems. We will cover Concurrency and Threading, Garbage Collection and Memory Management, Performance and Optimization, and more.
Speaker one bio:
A pragmatic and analytical software engineer with over two decades of experience, I believe in making reasoned arguments and building simple, elegant solutions. I am passionate about robust testing and creating systems that are clear and maintainable. My experience includes everything from core Java to product management, with a constant focus on improving the craft of software development.Speakers Two:
Ryan Healey Senior Software Engineer @ LMAX
Talk: The developers worked in two by two. Hoorah! Hoorah!Pair programming can be a rather polarising idea.Some people love the idea of working with a colleague, 2 heads are better that one when solving a complex problem. Some can see the benefits, but it’s just not for them, they’d rather work alone and focus. Others see pair programming as intimidating or toxic, why should I need someone sitting over my shoulder judging my every keystroke? Finally, managers think pair programming is a waste of precious resource, why should I pay 2 people to do 1 person’s job? Well, let's have the debate.
Let’s explore the pros and cons of pairing. When pair programming makes sense, and when it doesn’t. How to make a pairing session effective and what habits you might have that are sabotaging your pairing time. What makes a good pair and what makes a bad pair. What is extreme programming, and does it work?
Finally, it wouldn’t be a talk these days if I didn’t mention AI. Does AI change the way we pair program? Can you pair program with AI?Hopefully some of you will give pairing another go. Maybe others will see the faults in their ways and fix the bad habits they have in pairing. And maybe even some of you might realise that management was right all along, why are they paying 2 of us to do 1 person’s job. Let’s find out.
Speakers two bio:
Bioengineer turned programmer with 5 years professional experience at THG and LMAX, Ryan might not have as much experience in the game compared to most but he's keen to learn and eager to share what he's learnt. He's a strong believer that coding should be fun and easy and hopes that he can help make your lives fun and easy too.This event is organised by RecWorks on behalf of the London Java Community.
The London Java Community is sponsored by Hazelcast, Neo4j, Redis, and Discover
You can see our latest jobs here
You can see our privacy policy here
Continue the conversation at our Slack Group: https://londonjavacommunity.slack.com
Sign up here if you're not a member: https://bcrw.typeform.com/to/IIyQxdPlease register on Eventbrite to join this event.
Not open - LJC Meet-up at Tessl with VJUG and Neo4JTessl AI Limited, London
Please register on Eventbrite to join this event.
*** Please note this eventbrite is for the in-person side of this event.
You do not need to register to watch the event.***This hybrid event brings together the global vJUG audience with the vibrant London Java Community for an evening of world-class Java learning, community, and connection.
We’ll kick things off with Simon Maple exploring Spec Driven Development, showing why structured prompts are the key to scaling AI coding. Then, Andreas Kollegger, Lead for GenAI Innovation at Neo4j, will dive into Agentic Memory – Ripples of the Matrix, a thought-provoking exploration of how memory in time and space shapes the way agents collaborate, compete, and evolve. Finally, Holly Cummins will demonstrate Using LangChain4j to Make Your Java Apps Smarter, showing how to harness AI frameworks to integrate LLMs with real-world Java applications.
Whether you’re tuning in from around the world on YouTube or joining us in person at Tessl HQ with the LJC, expect insightful talks, lively discussion, and of course, pizza and beer for those in London!
Huge thanks to our friends at Tessl for sponsoring this event and supporting our community.
Location:
Tessl AI Limited, 210 Pentonville Rd, London N1 9JY.
Virtual: https://www.youtube.com/live/8l1obGG_6jQAgenda:
6:00pm – Doors open
6:30pm - Kick off and message from our partners
6:45pm – Session kicks off (live stream begins on YouTube with vJUG)Session 1: Spec Driven Development Why your prompt chaos won’t scale with Simon Maple
Session 2: Using LangChain4j to Make Your Java Apps Smarter with Holly Cummins
Session 3: Agentic Memory - Ripples of the Matrix with Andreas Kollegger
(live stream ends)
8:00pm – Networking
9:00pm – Wrap-upSession 1: Spec Driven Development Why your prompt chaos won’t scale
This session introduces Spec Driven Development (SDD) for AI coding, replacing ad-hoc prompts with human-readable specifications to improve code reliability, collaboration, and adaptability. We'll show this with a real-world Spring PetClinic example to show how SDD enables scalable, testable AI development, addresses challenges like spec drift, and supports smoother iteration and teamwork beyond freestyle prompting.Simon Maple - Head of Developer Relations
Simon Maple is the Founding Developer Advocate at Tessl, previously the Field CTO, and VP Developer Relations at Snyk, ZeroTurnaround, and IBM. He has been a Java Champion since 2014, JavaOne Rockstar speaker in 2014 and 2017, Duke’s Choice award winner, Virtual JUG founder and organiser, and London Java Community co-leader. He is an experienced speaker, having presented at most large conferences in the Java and Security spaces.Session 2: Using LangChain4j to Make Your Java Apps Smarter
AI isn't just for coding assistants and python programmers. The real power of LLMs comes from integrating them into applications, connected to real data and real business logic.
LangChain4j is emerging as a de facto standard for LLM integration in Java.In this demo-driven talk, Holly will explore a range of cool LangChain4j capabilities, such as type safe object mapping, stateful context, agents, RAG, guard rails, and fault tolerance. (The demos will use Quarkus, but LangChain4j can be used with any framework.)Holly Cummins, Senior Technical Staff Member, Quarkus at IBM
Holly Cummins is a Senior Principal Software Engineer on the Red Hat Quarkus team and a Java Champion. Over her career, Holly has been a full-stack javascript developer, a build architect, a client-facing consultant, a JVM performance engineer, and an innovation leader. Holly has led projects to understand climate risks, count fish, help a blind athlete run ultra-marathons in the desert solo, and invent stories (although not at all the same time). She gets worked up about sustainability, technical empathy, extreme programming, the importance of proper testing, and automating all the things. You can find her at http://hollycummins.com, or follow her on socials at @holly_cummins.Session 3: Agentic Memory - Ripples of the Matrix by Andreas Kollegger
The first drop seem innocent, refreshing almost. An agent's chain-of-thought descends from the sky, impacting the surface of our reality. Then more drops. Puddles form and ripples become interference patterns. Eventually, we're swimming in a digital sea. But seriously, let's talk about two dimensions of memory: time & space - working, short-term, long-term memory - single-agent, multi-agent, distributed scopes - collaborative, misaligned, competitive goalsAndreas Kollegger, Lead for GenAI Innovation at Neo4j
***Whether you're attending in person or joining us online, don't miss this opportunity to learn about the latest Java advancements and connect with the global Java community!
This event is organised by RecWorks on behalf of the London Java Community.
The London Java Community is sponsored by Hazelcast, Neo4j, Redis, and Discover
You can see our latest jobs here
You can see our privacy policy here
Continue the conversation at our Slack Group: https://londonjavacommunity.slack.com
Sign up here if you're not a member: https://bcrw.typeform.com/to/IIyQxdPlease register on Eventbrite to join this event.
Not open
