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Toronto Java Users Group

Toronto, ON, CA

4,573 members · Public group

Organized by Adib Saikali and 5 others

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What we’re about

The Toronto Java Users Group provides presentations of exciting new technologies and socialization with your fellow developers in a relaxed atmosphere. Join us for dinner, drinks, and a talk on an interesting topic presented by one of your peers. We have been meeting regularly since 2009, and aim to provide a safe and inclusive space for all regardless of gender, religion, race, sexuality or identity.

Upcoming events (3)

Thu, Aug 28, 2025, 6:30 PM EDTArchitect's Guide to Managing a Code Base - Pratik Patel
Free Times Cafe, Toronto, ON
As an architect you're often working at a high level on projects, thinking of architectural concerns such as distributed applications, CI/CD pipelines, inter-team APIs, and setting standards. Code quality affects everything that a software architect needs to work on - from a small way to a big way.

In this talk, we'll look at techniques and tools for managing code quality. Our goal as architects is to maximize the manageability of code, consider different coding paradigms and their effect on the six areas, and how to create habits and processes to ensure long term code viability. We'll take a couple of sidebars on performant vs manageable code and OO vs Data Oriented coding. We'll look at tools for doing static analysis vs dynamic analysis.

About the venue
Free Times Cafe has bistro-style seating and a full food and drink menu. Please consider helping to support the venue by planning to have supper during the talk.

Presenter Info
Pratik Patel - Developer Advocate @ Azul Systems

Pratik Patel is a Java Champion and developer advocate at Azul Systems and has written 3 books on programming (Java, Cloud and OSS). An all around software and hardware nerd with experience in the healthcare, telecom, financial services, and startup sectors. He's also a co-organizer of the Atlanta Java User Group and North Atlanta JavaScript meetup, frequent speaker at tech events, and master builder of nachos.
38 attendees+33
Thu, Sep 25, 2025, 6:30 PM EDTTJUG&ScalaTO: Simpler Java build tools with Object Oriented Programming-Haoyi Li
Free Times Cafe, Toronto, ON
This is a joint event hosted by the Toronto Java User Group and Scala Toronto.
Join us for a cross-community meetup featuring Haoyi Li on Simpler Java build tools with Object Oriented Programming. We'll kick off with brief introductions from each group before diving into the main talk.
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The Java language is known to be performant, easy to use, and with great IDE support, but Java build tools like Maven or Gradle do not always live up to that reputation. This talk will explore why build tooling is fundamentally such a difficult domain to work in, and how common concepts from object-oriented programming have the potential to simplify the build tool experience. We will end with a demonstration of an experimental new Java build tool "Mill" that makes use of these ideas, proving out the idea that Java build tooling has the potential to be much faster, safer, and easier than it is today.

About the venue
Free Times Cafe has bistro-style seating and a full food and drink menu. Please consider helping to support the venue by planning to have supper during the talk.

Presenter Info

Name: Haoyi Li

Li Haoyi graduated from MIT, has built infrastructure for high-growth companies like Dropbox and Databricks, and has been a major contributor to the open source community with over 10,000 stars on Github. Haoyi has deep experience in the JVM and has used it professionally to build cloud infrastructure, distributed backend systems, programming languages, high-performance web applications, and much more.
34 attendees+29
Thu, Oct 30, 2025, 6:30 PM EDTComparing Java startup performance options with Quarkus - Mark Stoodley
Free Times Cafe, Toronto, ON
Quarkus is a lightweight Java application framework that brings developers joy and supports deployment with both full powered Java Virtual Machines and Graal native images. In this talk, we'll look at other options that can be used to improve Java startup performance between these two "end points". We'll discuss different startup performance experiences that can be used to reuse classes, reuse compiled code, checkpoint JVMs, and employ remote JIT compilers. At the same time, we shouldn't ignore any implications on how long these other options will take to get to peak performance, how much memory will be consumed under load, and what peak performance your application might ultimately reach. Maybe there's a different point on the spectrum that will be just right for your applications? Come to this session to learn more about the trade-offs available to Quarkus applications to get the start-up speed you need, maybe without having to give up on any of Java's great features.

About the venue
Free Times Cafe has bistro-style seating and a full food and drink menu. Please consider helping to support the venue by planning to have supper during the talk.

Presenter Info
Mark Stoodley - Chief Architect for Java at IBM

Mark joined the IBM Markham lab in 2002 after graduating from the University of Toronto with a Ph.D. focusing on computer architecture and compiler optimization. He spent his entire IBM career in the Runtime Technologies (formerly Java Technology Center) team developing, testing, servicing, and architecting Just-In-Time (JIT) compilers. Mark led the J9 Java Virtual Machine team through the effort to significantly refactor and then to contribute millions of lines of J9 source code to two open projects : Eclipse OMR and Eclipse OpenJ9. Following this successful effort, he became the Chief Architect for Java at IBM, leading a global team that builds, innovates in, and services the IBM Semeru Runtime (JDK) for thousands of Java-based products and cloud services used by developers and small, medium, large, and huge companies spanning all sectors of the IT industry.
26 attendees+21

Past events (111)

Thu, Jul 31, 2025, 6:30 PM EDTJSpecify and the Nullness Checker: avoiding Null Pointer Exceptions-Werner Dietl
This event has passed
66 attendees+61

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