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Program Committee Member: Tony Printezis

JVM/GC Engineer @Twitter & Twitter Rep at JCP Executive Committee

Tony Printezis is a Staff Software Engineer at Twitter and a member of the VM Team in the Infrastructure Organization. He has over 20 years of virtual machine implementation experience with special focus on memory management. Most of his projects have involved improving the performance, scalability, responsiveness, parallelism, concurrency, monitoring, and visualization of garbage collectors. He was one of the designers of (and tech lead of) the G1 GC and the original implementer of the CMS GC.

Before Twitter, Tony worked at Adobe, the Java organization at Oracle and Sun Microsystems, and Sun Microsystems Laboratories. He holds a PhD and a BSc(Hons) in Computing Science, both from the University of Glasgow in Scotland.

Find Tony Printezis at

Interview

Question: 

What are you currently working on?

Answer: 

I work in the Twitter VM Team and we maintain, release and improve TwitterJDK, which is our internal JDK release most Twitter services use. It's basically OpenJDK with a bunch of custom changes and improvements. We try to use the latest update of the major Java version we are on for all the obvious reasons: security patches, bug fixes, etc. And we have added a fair amount of additional stuff to address any performance or other issues that we’ve come across in our data centers. We don't do anything for the sake of it. We do everything based on what we observe in our data centers. A lot of our changes involve profiling and trouble-shooting in production, which is why I proposed the Trouble-Shooting In Production track: it’s an important topic for us and a lot of other companies. These days, my team’s major project is migrating from Java 8 to Java 11. We're still in the process of doing that. We have a pretty stable release for Java 11. I did a lot of work to get that release ready for prime time. And we’ve started migrating services over. Any other changes that we want to do to our 11 release, I'll be working on that. And helping teams move over.

Question: 

What was your first experience with QCon?

Answer: 

I was in 2015. Monica Beckwith was the track host for the Java track and she invited me to speak. The week before I spoke at Devoxx in Belgium. It was more or less the same presentation. What I had to do was to fly to Belgium, then I flew directly to San Francisco from Belgium for QCon, and I then went home. That was a long trip. That was my first exposure to QCon. I spoke once after that, again in San Francisco, and I’ve attended QCon NY a few times. Once Twitter was an exhibitor and I spent some time at our booth. A couple of years ago, Twitter sponsored an entire track and I was the track host for that. We had presentations on the entire Twitter stack, from hardware/OS up to observability. That was really cool. I have been to QCon SF 3 times and QCon NY probably 4 times.

I have been a big advocate of the QCon conferences. One of the reasons is the attention to detail. They always try to have a good chunk of time between sessions, because a lot of the most important stuff that happens during conferences is the discussions between sessions, who you talk to, who you meet, etc. And I love the fact that I don't have to run from one session to the other and the speakers don’t have to rush setting up or tearing down. You know, after you finish you have to hurry because you have two minutes… it's a much better experience when you can take your time. The food is also great, some of the best I've ever had at a conference.

Question: 

Can you say a few things about what it was like being a speaker?

Answer: 

I used to be super nervous speaking in front of even five people. Then I was an academic for a couple of years and I had to speak several times per week, so I got over that. It's a case of if you keep speaking frequently you’ll get used to it sooner than later. I've spoken in front of 14 hundred people at JavaOne. But it was a long time ago. It's been easy for me since then. What I'm worried about is not about how I am going to deliver the material, but I want to make sure that the material is good and that people are going to learn something from it.

Question: 

What are some of the topic areas that you're most excited about?

Answer: 

I'm clearly biased because my interests are very focused. I'm always interested in hearing the Java track, what people are up to and what new technologies are coming up.

QCon is a great conference, and it has a very good breadth. I was mostly used to Java conferences in the past. Interesting to see that there are other things besides Java! I also really like the Optimize Yourself track. I don't know that many conferences that do that.

Tracks