June 2025 – Natan Code

Timezones in Java: How to Schedule Classes Correctly Across Time Zones?

Imagine you’re developing a platform like Cambly, where students and teachers are spread across the globe. A student in Brazil wants to schedule a class at 10:00 AM local time with a teacher living in Australia. How can you ensure that both are connected at the right time, even though they’re in different time zones?…

How to avoid race condition in shared resources in Java?

Sharing resources between threads can be a challenging task, as it requires ensuring that operations are atomic. What is a resource? A resource can be variables, data structures, files, messages, etc. In Java, we have two important memory areas: the Stack and the Heap. Why use shared resources between threads? There are many reasons, but…

How to use Kafka with Quarkus?

Apache Kafka is one of the most popular solutions for large-scale distributed event streaming. Its ability to handle high volumes of messages makes it ideal for event-driven architectures. In this post, you’ll learn how to use Kafka with Quarkus, a modern framework for cloud-native Java applications. Best of all: Quarkus’ Kafka support also works with…

What are Checked vs Unchecked Exceptions in Java?

In Java, exceptions are part of the Throwable hierarchy and are used to signal abnormal situations during the execution of a program. Understanding how exceptions are structured helps in designing more robust and readable code. At the top of the hierarchy is the Throwable class, which has two direct subclasses: Checked Exceptions Checked exceptions are…