Daniel Oh

CORE

Senior Principal Developer Advocate at Red Hat

Brookline, US

Joined Jul 2016

About

Java Champion, Developer Advocate, Technical Marketing, CNCF Ambassador, Keynote Speaker, Published Author

Stats

Reputation:	2334
Pageviews:	447.7K
Articles:	27
Comments:	9

Expertise

Cloud Architecture

Articles

Infusing AI into Your Java Applications

An introductory tutorial for Java developers on writing AI-infused applications using Quarkus with LangChain4j. You don't need Python to write AI apps.

October 10, 2025

· 6,108 Views · 10 Likes

The Future of Java and AI: Coding in 2025

Explore how Java developers are leveraging AI and modern frameworks like Quarkus to build cutting-edge applications in 2025.

May 21, 2025

· 5,742 Views · 4 Likes

Building a Simple RAG Application With Java and Quarkus

With Java’s versatility and Quarkus’s cloud-native optimizations, you can build high-performance, scalable applications that seamlessly integrate AI-driven features.

February 21, 2025

· 8,995 Views · 6 Likes

How To Get Started With New Pattern Matching in Java 21

Dive into pattern matching, a powerful new feature in Java 21 that lets you easily deconstruct and analyze data structures. Follow this tutorial for examples.

March 26, 2024

· 9,361 Views · 15 Likes

Demystifying Virtual Thread Performance: Unveiling the Truth Beyond the Buzz

Virtual threads can provide high enough performance and resource efficiency based on your concurrency goal but also let you have a simple development model.

December 5, 2023

· 13,278 Views · 9 Likes

Taming the Virtual Threads: Embracing Concurrency With Pitfall Avoidance

Learn what challenges you probably face when you try to run your microservices on the virtual threads. The challenge might be more complex and bigger if you need to import more Java libraries.

December 3, 2023

· 10,570 Views · 4 Likes

Quarkus 3: The Future of Java Microservices With Virtual Threads and Beyond

Learn how Quarkus integrates the virtual thread for Java developers to run blocking applications with a single @RunOnVirtualThread annotation.

December 1, 2023

· 20,861 Views · 9 Likes

Dynamic Data Processing Using Serverless Java With Quarkus on AWS Lambda by Enabling SnapStart (Part 2)

Learn outer loop practices in production using AWS Lambda and DynamoDB in part 2 on making serverless Java for dynamic data processing with a NoSQL database.

May 11, 2023

· 9,875 Views · 8 Likes

Dynamic Data Processing Using Serverless Java With Quarkus on AWS Lambda (Part 1)

This step-by-step tutorial explores how Quarkus enables Java developers to implement serverless functions on AWS Lambda to process dynamic data on AWS DynamoDB.

May 1, 2023

· 8,946 Views · 5 Likes

Build a Quarkus Reactive Application Using Kubernetes Secrets

In this post, learn how to follow security policies while developing applications for the cloud by using Kubernetes Secrets.

June 6, 2022

· 5,623 Views · 3 Likes

Extend Kubernetes Service Discovery With Stork and Quarkus

Quarkus enables developers to integrate client-based load balancing programming using Stork and Consul for reactive Java applications.

April 15, 2022

· 4,597 Views · 3 Likes

Java Serverless Functions With Quarkus Quick Starts

Getting started with your first Java serverless function using a Quarkus quick start.

April 6, 2022

· 5,728 Views · 6 Likes

Simplify Java Persistence Implementation With Kotlin on Quarkus

This article demonstrates how Quarkus enables developers to simplify JPA implementation using Kotlin programming APIs for reactive Java applications.

April 6, 2022

· 4,791 Views · 5 Likes

Get Started With Reactive Programming With Kotlin on Quarkus

In this article, learn how Quarkus enables developers to keep using Kotlin programming APIs for reactive Java applications.

March 24, 2022

· 3,442 Views · 4 Likes

What's New With Java 17 and Containers?

Quarkus allows developers to start a new application development based on OpenJDK 17. Read the tutorial below to find out how!

March 16, 2022

· 4,939 Views · 5 Likes

Simplify Java Persistence Using Quarkus and Hibernate Reactive

This tutorial shows how you can simplify reactive Java applications that persist data using the Hibernate ORM with Panache extension in Quarkus.

January 14, 2022

· 13,411 Views · 8 Likes

Visualize your Apache Kafka Streams using the Quarkus Dev UI

December 11, 2021

· 15,241 Views · 1 Like

Boost throughput with RESTEasy Reactive in Quarkus 2.2

With the new 2.2 release, Quarkus continues to improve in terms of network-related features, reactive programming, and integration with the Eclipse Vert.x event bus.

November 9, 2021

· 6,386 Views · 1 Like

A Java developer's guide to Quarkus

A new eBook demonstrates how developers can keep using the Java framework to build new serverless functions.

August 13, 2021

· 15,100 Views · 6 Likes

Bind a Cloud Event to Knative

CloudEvents provides a common format to describe events and increase interoperability.

July 6, 2021

· 9,840 Views · 2 Likes

Making portable functions across serverless platforms

Quarkus Funqy brings portability to serverless functions

June 15, 2021

· 8,517 Views · 3 Likes

Get Started With Java Serverless Functions

Quarkus allows you to develop serverless workloads with familiar Java technology.

June 4, 2021

· 13,487 Views · 7 Likes

What Is Serverless With Java?

The serverless development model is now a requirement for enterprises that want to spin up their business applications on-demand rather than running them all the time.

Updated May 22, 2021

· 23,620 Views · 36 Likes

Getting started with Java Serverless Functions using Quarkus and AWS Lambda

Java serverless functions with Quarkus

May 14, 2021

· 16,558 Views · 2 Likes

Build Even Faster Quarkus Applications With fast-jar

Quarkus is already fast, but what if you could make inner loop development with the supersonic, subatomic Java framework even faster? Introducing the fast-jar format!

April 15, 2021

· 8,445 Views · 4 Likes

Set Up Network Parental Controls on a Raspberry Pi

With minimal investment of time and money, you can keep your kids safe online.

March 11, 2021

· 23,037 Views · 5 Likes

What Makes Java Open-Source?

Navigating Java from an open-source perspective can be a bit confusing given the language's long history, acquisitions, and relicenses.

January 24, 2021

· 6,529 Views · 5 Likes

Refcards

Refcard #362

Getting Started With Quarkus Serverless Functions

Comments

How To Get Started With New Pattern Matching in Java 21

Apr 05, 2024 · Daniel Oh

Good catch. My bad. It shouldn't be a Dog object or Integer type. I removed that section. It will be republished soon.

Visualize your Apache Kafka Streams using the Quarkus Dev UI

Dec 15, 2021 · Daniel Oh

Cool. Thanks for sharing!

A Java developer's guide to Quarkus

Sep 09, 2021 · Daniel Oh

I can't still agree that VPS can solve all business problems and is a cheaper maintenance cost than serverless cloud. It will vary business domains, workloads, seasonality, topology, human resources.

A Java developer's guide to Quarkus

Sep 08, 2021 · Daniel Oh

Thanks for sharing your thoughts. I agree that cost is always important to manage the business but I disagree traditional infrastructure(VMs) can leverage all workloads for scalability, performance, reliability. Also, serverless is not "cloudfull" but the serverless functions should be scaled down to zero when there's no demand at all. It means all relevant resources are free then you don't need to pay for that. If you have bad experiences with serverless, esp cost stuff, I'd say you need to optimize the application first to fit in Serverless architecture. What language, framework, package do you use to run functions on the cloud? If you have Knative on prem Kube, you can build your own serverless platform as well :)

What Is Serverless With Java?

Jun 05, 2021 · Daniel Oh

Thanks! Node means Kubernetes worker node. HotSpot box means Java which is the lowest density to run app pods.

What Is Serverless With Java?

May 25, 2021 · Daniel Oh

Yeah, native compilation will be one of the next topics.

What Is Serverless With Java?

May 24, 2021 · Daniel Oh

Stay tuned! It will come up soon :)

What Is Serverless With Java?

May 24, 2021 · Daniel Oh

Thanks, James! It will come soon!

Build Even Faster Quarkus Applications With fast-jar

Apr 15, 2021 · Daniel Oh

When you run the Quarkus development mode(i.e. mvn quarkus:dev), you don't need to recompile, rebuild, repackage, restart runtime whenever you change code since Quarkus does it automatically which means developers can save time for those jobs.