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London Java Community

The home for those who work with Java and the JVM

What is LJC about?

The LJC is a broad community of technologists and other associates with Java and JVM-related technologies. Although it is based in London, UK – it has some international membership due to its global programmes (such as Adopt a JSR and Adopt OpenJDK). The LJC hosts regular events including casual catch-ups in a cafe, hack days, evening talks, unconferences, workshops, mentoring, demos, a career mentoring by London’s
Java specialists and much more.

The LJC acts as a voice for Java engineers in London UK as well as globally. This includes but is not limited to creating Adoptium, the world’s leading OpenJDK distribution, representing Java developers worldwide on the Java standards body, and contributing towards charitable works.

Upcoming Event

LJC Live at LMAX with Trisha Gee

LJC Live is back and we’re thrilled to welcome back Java Champion, Trisha Gee and grateful to our hosts LMAX. Agenda 6pm Arrivals and drinks 6.20pm Welcome from the LJC 6.25pm Welcome from Andy Philips, CTO, LMAX 6.30pm Ed Worthy presentation: ‘Fast Feedback’ 7pm Break for refreshments, sponsored by Gradle 7.30pm Trisha Gee presentation: Are your tests slowing you down? How a Developer Productivity Engineering (DPE) approach can speed up writing, running and debugging tests. 8.15pm Q&A and networking 8.45pm Departures Speaker: Ed Worthy, Lead Developer, LMAX Group Title: Fast Feedback Synopsis: How to break things quickly and safely, and then fix processes over the long term. This presentation will cover some of best practices for improving efficiency across multiple stages of the software development lifecycle with some stories and examples from our developers experiences. Speaker: Trisha Gee, Lead Developer Advocate, Gradle Title: Are your tests slowing you down? How a Developer Productivity Engineering (DPE) approach can speed up writing, running and debugging tests. Synopsis: Testing is a Good Thing, right? Especially automated testing. But "Good things come to those who wait" is not something that's going to appeal to the busy developer. You want results, and you want them now. You're in The Zone working on a problem, and the last thing you want is to break your flow wrestling with your testing framework or waiting for the tests to finish running. More code means more tests. More coverage means more tests. More tests mean more time. Time that you want to spend being productive, creative, innovative. How can you balance the need for quality with the need for speed? In this talk, Trisha will identify issues that slow down developers when writing, running and debugging tests, and look at tools that can help developers with each of these problems. There will be live coding, analysis of social media poll results, an overview of solutions in this space, "best practice" recommendations, and machine learning will be mentioned at some point. Speaker bios: Trisha Gee is a software engineer, Java Champion and author. Trisha has developed Java applications for a range of industries of all sizes, including finance, manufacturing and non-profit, and she's a lead developer advocate at Gradle. She has expertise in Java high-performance systems and dabbles with Open Source development. Trisha’s exceptionally passionate about sharing things that help real developers. That might be: getting them up to speed on the latest version of Java; teaching them tips and tricks to improve their productivity; or promoting healthy technical communities across the globe. Trisha values helping all developers level up their career and skills at every step of their journey. Read more from Trisha in the books “Head First Java”, “Getting to Know IntelliJ IDEA”, “97 Things Every Java Developer Should Know” and “What to Look for in a Code Review”. Ed Worthy is a software developer who's been around the block in the fintech industry and has seen the good, the bad, and the ugly sides of software development. He's passionate about best practices, performant / reliable code, and developer productivity. This event is organised by RecWorks on behalf of the London Java Community. The London Java Community is sponsored by Hazelcast, Vonage, and Discover










The next event is coming soon!

Our Initiatives

The LJC has many initiatives, all volunteer lead and founded by our organisers and members. Read about our initiatives below.


The Eclipse Foundation is a non-profit organisation that supports open source software development. It provides a place for developers to collaborate on and innovate open source projects. The Eclipse Foundation also provides services to the Eclipse community, such as IP management, ecosystem development, and marketing.

The LJC has a seat on the JCP and runs the Adopt a JSR programme for Java SE (at OpenJDK), Java ME and Java EE (now Jakarta EE).

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The LJC works on OpenJDK, and co-founded Eclipse Adoptium (the successor to AdoptOpenJDK), the world’s leading FREE OpenJDK distribution!


The LJC is a founding member of –
a new community around building a defacto set of API’s and implementations for Microservices in Java.


The LJC is a founding member of Jakarta EE / EE4J – the new home for Java EE at the Eclipse Foundation.


Sponsor the LJC

The LJC has a multitude of events and global initiatives impacting hundreds of thousands of developers due to the generosity of Recworks, volunteers and key sponsors. You can donate directly or talk to us about a sponsorship package.

Talk to us on Slack

Our LJC Slack group is a vibrant real time community where you can speak with your fellow technologists and world leading experts about topics that matter to you!


Barry Cranford

Founder / Co-organiser

Know More About Us?

Since it’s inception, RecWorks have always invested in and sponsored the London Java Community both in terms of time and money to power the events. Over the years that relationship has now become more official in that for any placement which came through an LJC event, RecWorks now gives a % of all the placements back to the community. 

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