Duke's Corner Podcast

Jim Grisanzio from Oracle Java Developer Relations talks with Carlos Obregón at JavaOne 2026. Carlos is a Java Champion and also the founder of Bogota's Java User Group, Bogotá JVM. Carlos has been running monthly meetups for over a decade, and he and his colleagues have built one of the most active developer communities in Latin America. In his session at JavaOne — Teaching Java as a First Language: Lessons from Three Years of a Real-World Bootcamp — he outlined a free, online, 13-week week program for learning Java. The bootcamp started in Colombia but then quickly expanded to include multiple JUGs in Latin American."Java is the best language for this" he said. The community, the tooling, the syntax, the readability of the language itself — everything pointed in the right direction. And the students in the bootcamp agree. "They love Java" he said. Carlos started out programming in C++ in school, but from the moment he finally picked up Java it was obviously different. "It was Love at first sight" he said.Carlos also advises that developers embrace AI. "Think of it like your pair programming buddy," he said. But he said to go deeply into programming fundamentals first because if you can't evaluate what the AI produces then you may end up shipping bugs you don't understand.JavaOne was an amazing experience for Carlos. It was his first JavaOne, but he'll be back for sure.

Jim Grisanzio from Oracle Java Developer Relations talks with Cristian Schuszter at JavaOne 2026. Cristian is a PhD in systems engineering and a Tech Lead at CERN in Geneva. He’s been at CERN for 8 years, but he’s been coding since he was eight years old. He loves working with and contributing to the Java community and other Open Source projects. This was Cristian’s first JavaOne, and his session, “30 Years of Java Development: Keeping it All Together,” covered how CERN keeps Java running across teams since 1998. Like any large company, CERN uses a lot of legacy code supporting systems that, in Cristian’s words, “need to keep running.” Java is not only used for business critical applications at CERN but also for accelerator system operations. On working at CERN among Nobel laureates, Cristian said, “I felt like I thrived in this kind of environment.” Cristian also helped revive the Voxxed Days developer conference at CERN and started the CERN Java User Group.

Jim Grisanzio from Oracle Java Developer Relations talks with Cristian Schuszter at JavaOne 2026. Cristian is a PhD in systems engineering and a Tech Lead at CERN in Geneva. He’s been at CERN for 8 years, but he’s been coding since he was eight years old. He loves working with and contributing to the Java community and other Open Source projects. This was Cristian’s first JavaOne, and his session, “30 Years of Java Development: Keeping it All Together,” covered how CERN keeps Java running across teams since 1998.

Like any large company, CERN uses a lot of legacy code supporting systems that, in Cristian’s words, “need to keep running.” Java is not only used for business critical applications at CERN but also for accelerator system operations. On working at CERN among Nobel laureates, Cristian said, “I felt like I thrived in this kind of environment.” Cristian also helped revive the Voxxed Days developer conference at CERN and started the CERN Java User Group.

Jim Grisanzio from Oracle Java Developer Relations talks with Martin Chalupa from Netflix at JavaOne 2026. Martin is a software developer with about eight years at Netflix and about twenty years working with Java. At Netflix, Martin works on the JVM ecosystem team, which grew from the build tooling team and now also handles broader JVM work such as tuning, garbage collection, and upgrading. In his session at JavaOne Martin covered Java ahead of time compilation and Project Leyden, and he shared what Netflix has learned from experimenting with the technology.

Just as many software developers, Martin found his way into engineering through this experience gaming as a kid. He built his first game in Java for the old Nokia phones as a school project. He has watched Java change a great deal over the years. The language keeps getting more comfortable and more approachable for young developers. His advice for students is to explore different options and find their own passion in the work. “With a little bit of work you can achieve some cool stuff,” he says. So, get out there and “discover your passion.”

Jim Grisanzio from Oracle Java Developer Relations talks with Luiz Real, an engineer and college professor from the SouJava Community in Sao Paulo, Brazil. Luiz came to JavaOne 2026 for the first time this year to build relationships, catch up on the latest technical features in Java, and to mix with the Java Champions. He says building those connections is something you can only do in person at a conference like this. “JavaOne for me is a career changing thing,” he says.

Luiz has been around Java for 18 years and working with it professionally for at least eight years. He’s a lead software developer at a large university and currently building digital management systems. The university runs more than 80 systems in Java. As he puts it, “Java in the enterprise world is, I think, the most reliable, the most used language.” Luiz is also a college professor, so he sees both sides of Java in industry and academic. His students are picking up Java because the jobs are there and they pay well. The hard part isn’t learning the language. It’s in the application. Students learn the fundamentals but sometimes struggle to apply them to real problems solutions. So Luiz brings real problem sets into class, works through them step by step, and explains what he’s doing as he goes.

On AI, Luiz sees real opportunities for Java developers. “Even in the AI era, we can do a lot more with AI now with Java,” he says. “You see language is a tool. I’m telling my students that if they want to learn they should learn as many tools as they can. This is very good for them because it’s just one more thing that they can put in their resumes and one more thing that can help them to achieve what they want and to solve the problems that the market presents to us.”

But there’s a catch he sees in his classroom regarding AI. Many students use AI to build things for them rather than to understand how those things work. So, he pushes students to ask the follow up questions about how the code they just built actually works. AI should be a tool for learning and extending their knowledge of Java development.

Luiz says his biggest opportunity for his career was when he joined the Java community. Everyone is so passionate about the language, he says, and willing to share what they know. “SouJava is one of the biggest communities in the world,” Luiz says. The community hosts at least one in person meetup a month, sometimes two or three. “Every month we get more than 100 people in person, and hundreds more online.” When SouJava partners with other communities, the events grow to 200-400 people in person. Everyone is a volunteer, from the registration desk to the speakers themselves. Attendees feel the energy and want to stay involved. They want to become friends and step up as the next speakers. SouJava also runs international sessions in English, in person and streamed live. “Everyone is welcome in our community.”

Jim Grisanzio from Oracle Java Developer Relations talks with Henri Tremblay at JavaOne 2026. Henri is a Java Champion, Montreal JUG leader, and EasyMock lead developer from Canada.

Henri’s session at JavaOne covered the Java Memory Model, which is a topic he believes every Java developer should understand well. He’s been to six JavaOne’s and had warm words for the conference, which represents a rare opportunity to meet the people whose code runs on systems and devices all over the world.

He has clear advice for developers: read books, understand how and why your code works, and get out there and join the community. Henri Tremblay on LinkedIn: https://www.linkedin.com/in/henritremblay/Jim Grisanzio on LinkedIn: https://www.linkedin.com/in/jimgris/

We also talked about why Java still powers so much of the world’s critical infrastructure, from banks to the Mars rover. Henri pointed out that companies often start in C++ and then move to Java because Java runs nearly as fast once it’s going and is far easier to change later.

On AI, Henri had a balanced view. He uses it for tedious work, like sifting through a gigabyte of logs to find a single error. But he was also clear about the risks. “We should not get lazy at reviewing code because AI will generate tons and tons of code. It’s not bad at reviewing it, but still it makes mistakes.” He warned that AI reflects the average of what’s on GitHub, and most code on GitHub isn’t great. Your role, he said, is to find a better answer.

For students and junior developers, he says they should also leverage AI for learning, but he advises that they internalize the fundamentals of software engineering deeply. “Read books, please, please!” He pointed to Core Java, the book he originally learned from and is now helping revise. Blogs and YouTube videos only tough on surface level issues. Books take you deep and that’s the knowledge you need to grow your career.

Jim Grisanzio from Oracle Java Developer Relations talks with Bruno Borges from Microsoft at JavaOne 2026. Bruno works on GitHub’s Core AI developer relations team. The conversation covers the future of Java in a world of AI, the value of learning core computer science fundamentals in school, the shifting role for software developers from just writing code to architecting higher level systems, the new business value opportunities for developers as they leverage AI technologies, and Bruno’s new AI-assisted website called Java Evolved that visually compares old and new Java code patterns.

Jim Grisanzio https://x.com/jimgrisBruno Borges https://x.com/brunoborges

Bob Treacy started his career as a union steward on the factory floor at GE Aircraft Engines. After earning a BS and MS in Computer Science from Boston University while also raising a family, he jumped into software, never looked back, and remains at the leading edge of Java and AI today. He picked up Java in the summer of 1995 at a training session in New York, and the language has been central to his work ever since. Today he is Principal Software Architect and Data Engineer at Harvard’s Institute for Quantitative Social Science, and he has attended more than 20 JavaOne conferences, which is most of Java’s lifespan.Getting to all those JavaOne events has always been non-negotiable. “Every job I’ve ever gone to, one of the things I demand is that I be able to go to conferences like JavaOne.” The reason, he says, is simple: “It brings a lot of different perspectives, sharing experiences, learning from each other, and just a great group of people.”At JavaOne 2026 he’ll present work from Harvard’s Dataverse project, an open source platform for preserving and sharing research data. The problem he is solving is straightforward but persistent because researchers treat the repository like a simple archive and skip the metadata that makes their datasets discoverable. His solution uses LLM embeddings and a graph database to compare new dataset descriptions against existing ones and recommend subject categories automatically.The conversation goes well beyond his upcoming JavaOne session itself. Bob lived Java’s entire evolution from the rough early days of applets through HotSpot, modularity, and the modern work on GPU access via Project Babylon and the Foreign Function and Memory API. On AI, he says that “I think there has to be a human in the loop.” He sees LLMs as causal models, not reasoning systems. “Given these words that came before, what’s the next word going to be? That’s not really intelligence. I don’t totally buy some of the narratives that are out there about AGI.” His advice to students is equally grounded in simplicity. He advises students to learn the code, but spend more time understanding how large systems work together. As he puts it, “just doing pure coding” is no longer enough.

This is the third in a short series of speaker profiles for JavaOne 2026 in Redwood Shores, California, March 17-19. Get early bird pricing until February 9, and for a limited time, take advantage of a $100 discount by using this code at checkout: J12026IJN100. Register. Sessions.In this conversation, Jim Grisanzio from Java Developer Relations talks with Paul Bakker, an engineer and Java architect in California. Paul is a staff software engineer in the Java Platform team at Netflix. He works on improving the Java stack and tooling used by all Netflix microservices and was one of the original authors of the DGS (GraphQL) Framework. He is also a Java Champion, he’s published two books about Java modularity, and he’s a speaker at conferences and Java User Groups.Java Is Everywhere at NetflixPaul will present “How Netflix Uses Java: 2026 Edition” at JavaOne in March. The session updates previous year’s talk because Java keeps evolving at Netflix. “Netflix is really staying on the latest and greatest with a lot of things,” Paul says. “We’re trying new things. And that means there’s always new stuff to learn every year.”Java powers both Netflix streaming and enterprise applications used internally and supporting studio teams. “Java is everywhere at Netflix,” Paul says. “All the backends, they are all Java powered.” Why Java? It comes down to history and practicality. The original team members were Java experts, but more importantly, “Java is also just the best choice for us,” he says. The language balances developer productivity and runtime performance. At Netflix’s scale with thousands of AWS instances running production services, runtime performance is critical.Netflix engineers stay closely connected with development at OpenJDK. They test new features early and work with preview releases or builds before official releases. When virtual threads appeared, Netflix engineers tested immediately to measure performance gains. Paul says they give feedback on what works, what doesn’t work, and what they would like to see different. This just demonstrates the value of being involved with OpenJDK, and Paul says they have a really nice back and forward with the Oracle engineering teams.The microservices architecture Netflix adopted years ago enabled the company to scale. This approach has become common now, but Netflix pioneered talking about it publicly. Breaking functionality into smaller pieces lets teams scale and develop services independently. Most workloads are stateless, which enables horizontal scaling. Production services for streaming often run several thousand AWS instances at a time.Early on with Java AppletsPaul’s coding journey started at 15 when he got his first computer and wanted to learn everything about it. Working at a computer shop repairing machines, the owner asked if he knew how to build websites. Paul said no but wanted to learn. He was curious about everything that involved computes. Java applets were hot back then. With nothing online available, he bought a book and started hacking away. “It was so much fun that I also decided right at that point basically like, oh, I’m going to be an engineer for the rest of my life,” he says.That’s clarity for a 15-year-old. And it’s remarkable. But Paul says it felt natural. He just started doing it, had such a good time, and knew that was what he wanted to do. When he started university around 2000, right during the dot-com bubble and crash, professors warned students not to expect to make money in engineering because the bubble had burst. Paul still remembers how funny that seems now. You can never predict the future.Initially, he learned Java and PHP simultaneously. Java powered client-side applications through applets while PHP ran server-side code. The roles have completely reversed now.Engaging the CommunityPaul attended his first JavaOne in 2006. “Those were really good times,” he says about the early conferences when everything felt big and JavaOne was the only place to learn about Java. Back then, around 20,000 people would travel to San Francisco every year. It was the one and only place to learn what was new in Java. All the major news would be released at JavaOne each year. The world has changed. Now information spreads instantly and continually online, but Paul misses something about those early days.The more recent JavaOne conferences offer something different but equally valuable. Paul points to last year’s event in Redwood City as a great example. While the conference is still big, it’s small enough that attendees can actually talk with the Oracle JDK engineers and have deeper conversations. The folks who work on the JDK and the Java language are all there giving presentations, but they’re also totally accessible for hallway chats. “That makes it really interesting,” Paul says. This direct access to the people building the platform distinguishes JavaOne from other conferences.Java User Groups also played an important role in Paul’s development. He lived in the Netherlands before moving to the Bay Area nine years ago. In the Netherlands, the NLJUG (Dutch Java User Group) organized two conferences a year, J-Spring and J-Fall. Paul would go to both every year. That was his place to learn in Europe. He has been continuing that pattern right up until now, which is why he is speaking at JavaOne again.Open Source software has also been another major aspect of community for Paul. He has always been active in Open Source because he says it’s a fun place to work with people from all over the world solving interesting problems. Besides being a critical part of his professional career, it was also his hobby. Paul says the Open Source aspect with the community behind it is maybe his biggest thing that he really enjoyed over the years.AI Throughout DevelopmentAI now occupies much of Paul’s professional focus. At Netflix, engineers use AI tools throughout the development lifecycle. Paul uses Claude Code daily, though other developers prefer Cursor, especially for Python and Node work. Most Java developers at Netflix work with Claude Code. The tools integrate with GitHub for pull request reviews, help find bugs, and assist with analyzing production problems by examining log files.Paul describes using AI as having a thinking partner to t all to and code with. Sometimes he needs to bounce ideas around, and the AI gives insights he might have missed or suggests additional issues to consider. For repetitive tasks like copying fields between objects, AI handles the grunt work efficiently. “That’s the nice thing about an AI,” Paul says. “While a person would probably get really annoyed with all this feedback all the time and like having to repeat the work over and over again, but an AI is like, fine, I’ll do it again.”Go Build a Lot of Stuff!When asked about advice for students, Paul’s answer comes quickly and has not changed much over the years. “I think what I really recommend is just go and build a lot of stuff,” he says. “The way to get to become a better developer is by doing a whole lot of development.”That’s timeless advice students can easily adopt no matter how the modern tools for learning have changed. Paul had to go to a bookstore and buy a book to learn programming. Students today have AI tools to help them and advanced IDEs. But the fundamental principle remains the same, which is to build interesting applications. Paul recommends that students come up with a fun problem and just build it. You learn by making mistakes. You build a system, reach the end, and realize the new codebase already struggles with maintainability. Then you ask what you could have done differently. Those real-life coding experiences teach you how to design code, architect code, and write better code.Paul also suggests that students use AI tools but not blindly. Do not just accept whatever an AI generates. Instead, try to understand what came out, how it could have been done differently, and experiment with different …

Jeanne Boyarsky: Get Ready for Java 25 Certification | Duke’s Corner Java Podcast, January 21, 2026

This is the first in a short series of speaker profiles for JavaOne 2026 in Redwood Shores, California, March 17-19. Get early bird pricing until February 9, and for a limited time, take advantage of a $50 discount by using this code at checkout: J12026DCP. Register. Sessions.

In this conversation, Jim Grisanzio from Java Developer Relations talks with Jeanne Boyarsky, a Java developer, an author, and a Java Champion based in New York City. Jeanne previews her JavaOne session, which will be a Hands on Lab for Java 25 certification. Previously, Jeanne was a guest on Duke’s Corner in January 2024: Jeanne Boyarsky on Java, Learning, and Contributing.

Preparing for Java 25 Certification

Jeanne will be running a hands-on lab about Java 25 and getting ready for the certification: Becoming One of the First Java 25 Certified Developers in the World (or Learning New Features). The session will cover features added to the language from Java 17 to Java 25. Although the certification has not been announced yet, Jeanne is already preparing for it. “You can be one of the first people in the world to be certified if you come to my talk and learn about it and are ready when the test comes out,” she says.

The lab will walk through tricky questions and edge cases featuring new functionality, with coding practice to explore the features directly. Even if you are not planning to take the certification test, the lab provides a good way to learn about the new features. The session is designed for beginners with one to three years of experience.

Top Features in Java 25

Several features particularly excite Jeanne. She highlights scoped values, which she describes as “a good jump from thread local in order to be able to share code in a nice, safe, contained way.” She also appreciates unnamed variables and unnamed patterns because developers no longer need to use annotations to suppress warnings for unused variables. “You can just use an underscore,” she says.

Jeanne is particularly interested in stream gatherers because streams are one of her favorite features in Java overall. She was excited when stream gatherers were in preview, and now that they are officially released, she can use them in her job. “Nice that the excitement hasn’t worn off, right?”

Among the new features, Jeanne is especially interested in the new main method, as described in JEP 495: Simple Source Files and Instance Main Methods. “I’m super, super, super excited about the new main methods where you don’t need a class and you don’t need the whole static void mess,” she says. This change makes writing code more succinct.

Making Java Accessible to Students

This change in how Java handles the main method enables new developers to learn Java faster. Jeanne volunteers at a high school teaching kids how to code in Java. In the past, teachers had to tell students: “Alright, public class foo, public static void. Don’t worry about what any of that means. We’ll tell you later.” But Jeanne says that curious kids would ask what it meant, and teachers could only say that comes later.

Now, students start with void main, braces, and IO print line. “It’s obvious what everything does,” Jeanne says. Void means it does not return anything, which makes sense to students. They can even use the Java Playground and start with just IO print line. When they move to the command line or an IDE, they only need the void main part without discussing the word class until they are ready to learn about classes and objects.

“It makes their first impression of the language so much better, and it makes it so much faster and easier for them to get started,” Jeanne says. She particularly appreciates the Java Playground because students do not need anything installed on their computers to start. They can write print lines, loops, and control structures, and by the time teachers ask them to install something, they are already invested in programming. “It’s fun.”

Jeanne calls the Java Playground “awesome” and says it’s a “really nice utility” even for experienced developers. She uses it herself for quick tests when she does not want to open an IDE.

JavaOne on Oracle’s Campus

When asked about JavaOne, Jeanne describes the conference as moving to California last year, just outside San Francisco on Oracle’s campus. “The weather was great, which is awesome because I live in New York City. There’s snow outside right now,” she laughs.

The venue particularly impressed her. “It was nice because it was on Oracle’s campus. You got a feel for it. It was pretty. There was a lake. There was a lot of areas to connect with people inside and outside.” The conference was held largely in one building, with lunch in another building nearby, which made it easy to engage people repeatedly. “Even if you don’t know people, the fact that they’re at JavaOne means they’re interested in Java. So, you can go over to anyone and introduce yourself.”

One of Jeanne’s favorite memories from a previous JavaOne was meeting Duke and seeing her book in the Java bookstore.

Advice for Students

When asked for advice for students learning computer science, Jeanne recommends learning the fundamentals while using AI to help. “Rather than using AI to write the code, have it give you practice questions or do code review or ideas of projects,” she suggests.

Students also often ask what professional developers do daily. Her answer provides a realistic picture of professional software development. “Every day is a little bit different, but most days include a mix of meetings, working with my coworkers, code reviews, writing code, now with AI,” she says. Problem solving takes many forms, from performance questions like “Why is this slow?” to security concerns about making systems more secure.

A significant part of her role involves understanding what users actually need. “A lot of the time users ask for what they think they want and not what they actually want,” Jeanne says. Through user interviews, she works to understand what they are trying to accomplish, which often leads to better solutions than what they initially requested. “So not just building what you’re told is a huge thing, especially as you become more senior in your career,” she says. The goal is to make users productive and happy, not just to code.

Technology keeps changing, and for Jeanne, that constant evolution makes the work fun. She has embraced AI tools as coding assistants, using them for pair programming, generating tests, and suggesting next steps. When her team piloted coding assistants, they focused on choosing a tool rather than waiting for the perfect tool. “The important thing is to get a tool and get people going and using it and being more productive,” she says. The learning curve is not high, and the tools pay for themselves almost immediately.

However, Jeanne says that it’s important to understand what you are doing rather than using AI to replace that understanding. “It’s about understanding what you’re doing and not using the AI to replace it because at least with the coding assistance, it’s right 90, 95% of the time,” she says. She talked about an example of asking AI to generate a regular expression while pairing with a junior programmer. The AI started writing it properly but then made an error. “I noticed it right away because I know what correct is,” she says. After giving it another prompt with a hint, it produced the correct result. Without knowing what correct looks like, developers cannot effectively verify and fix AI-generated code.

The AI Hype Cycle

Regarding concerns about AI making developers obsolete, Jeanne is pragmatic. “I’ve heard that enough times that I’m a little skeptical,” she says, adding that this is the third or fourth time some technology has been predicted to take all the jobs. Instead, she sees AI as enabling developers to accomplish more and make users happier. She has a big backlog “that goes on forever.”…