Thomas Wuerthinger discusses GraalVM, native compilation, and the performance trade-offs between JIT and AOT compilers.
GraalVM promises faster startup, lower memory usage, and predictable performance — but when does it actually beat the JVM as we know it?
In this episode of The Marco Show, Marco talks with Thomas Wuerthinger, Founder and Project Lead of GraalVM and Vice President at Oracle, about compilers, Java performance, native images, polyglot runtimes, and what really matters when software runs at scale.
Thomas shares why rebuilding runtimes for every language is a waste of engineering effort, how GraalVM grew from a research project into a production-grade platform, and why Native Image unexpectedly became its most impactful feature. They also unpack the One Billion Row Challenge, performance myths around JIT vs AOT, branch misprediction failures, cloud economics, Python and JavaScript runtimes, and the role of AI in compiler development.
This episode is a deep dive into how modern runtimes actually work — and how performance decisions play out in the real world.
🎁 Giveaway
How many lines of open-source code are maintained across GraalVM and its related language projects? Drop your guess in the comments 👇
Timestamps
– Intro
– Meet Thomas Wuerthinger & what GraalVM really is
– Why duplicating language runtimes is a waste
– How GraalVM started at Sun Microsystems Labs
– Writing an interpreter and getting a JIT “for free”
– Going open source and finding real users
– Why Native Image took off
– From research project to real product
– Native Image, Spring, Quarkus, and Java in the cloud
– Why JIT performance can be unpredictable
– When JIT still makes sense
– Python, JavaScript, and polyglot runtimes
– Using AI in compilers and testing
– The One Billion Row Challenge
– Branch misprediction and performance surprises
– How to think about performance optimization
– Giveaway question
– Rapid fire and wrap-up
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Why it's here
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What people say. Recommended for its deep dive into Java performance and the JIT versus AOT debate.
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u/mttdin r/Compilers • Recommends
"I would recommend JIT only if you absolutely have to use it" - The Future of Java: GraalVM, Native Compilation, Performance – Thomas Wuerthinger
The Future of Java: GraalVM, Native Compilation, Performance – Thomas Wuerthinger | The Marco Show: link to this video (about 35 minutes in)
> I mean the most obvious benefits to people was the startup. That's the thing that of course in nowadays social media-driven world was giving us the most viral content because you have a Java app and suddenly it starts in 5 milliseconds. Okay. A full Java server with Micronaut. So that's the number one benefit and that's why native image is used a lot in serverless environments for example where this fast startup is s…
