Java | Matheus Oliveira

Illustration of a ring of event loop threads, each serving many connections, with one blocked thread highlighted in red

Inside the Quarkus reactive core, part 1: the event loop from the ground up

I gave Quarkus two event loops and fired 24 requests at it at once. Every one was served by one of those two threads. Part one of a series on how Quarkus runs your code, starting below Quarkus: Netty, Vert.x and the rule you cannot break.

Illustration of a configuration file whose highlighted lines flow into a hexagon and come out as two dashed-outline blocks with plugs

Inside ArC, part 3: the beans nobody wrote

I found beans in my application’s bytecode that no class in the project declares. In part 3 of this ArC deep dive, I show how extensions create beans from configuration, why Quarkus doesn’t run Portable Extensions and how a Quarkus extension works inside.

Inside ArC, part 2: proxies, interceptors and the bean that vanished

A constructor that runs twice, an interceptor that works even on internal calls and a bean that doesn’t even exist at runtime. In part 2 of this ArC deep dive, I show what the Quarkus build changes in application code.

Illustration of an editor window with lines of code connected by an electric arc to a grid of blocks representing the generated bytecode

Inside ArC, part 1: the Quarkus CDI that runs before your code does

I opened the bytecode Quarkus generates for CDI to see what the container does before the application starts. Part one of a deep dive into ArC with real experiments: discovery, validation and a create() that is just a new.

SNES-style pixel art status screen showing eight stacked carriers: seven running in blue and one in red, locked behind a padlock, with threads queued up behind it

Virtual Threads: A Pocket Guide

What virtual threads solve, what they break, what happens when your database slows down, and why Java 25 made all of this far simpler than it was in 2023.

Trace waterfall of a single request: one fast root span above a descending ladder of forty identical SELECT queries

Observability in Practice: Why Instrument, and How Quarkus Makes It Cheap

Part 1 of 2. Why observability became the market standard after OpenTelemetry graduated from the CNCF, the minimum vocabulary to follow along, and what Quarkus gives you without writing a line of code.

Kafka Integration in Quarkus: Reactive Messaging, @Incoming and @Outgoing

Take messaging outside the application with SmallRye Reactive Messaging. Channels vs Topics, @Incoming, @Outgoing, Emitter, automatic JSON serialization, and Dev Services starting the broker without you installing anything.

Minimalist diagram showing four interconnected pillars labeled Style, Characteristics, Components, and Decisions, on a dark background

Software Architecture Fundamentals: the 3 laws and 8 expectations every developer should know

Everything in software architecture is a trade-off. A deep dive into Chapter 1 of Fundamentals of Software Architecture: the 3 laws that govern every architectural decision and the 8 expectations of an architect.

Minimalist diagram showing a central 'Agent' node connected to four modules: Soul, Memory, Skills and Tools, on a dark purple background

Qlawkus: Build Personal AI Agents in Java with Quarkus

Introducing Qlawkus, a set of Quarkus extensions for building personal AI agents in Java: memory that’s automatically injected, procedural skills, voice-enabled messaging, and composition via agent.yml.

Pixel art SNES 16-bit of a retro dispatch center with a robot operator routing glowing message packages through neon rails to three distinct receiver nodes, neon SIGNALS sign above

Internal Messaging in Quarkus: Signals, @Receives, and the New Publisher-Subscriber Pattern

Decouple components with Quarkus Signals. Type-safe resolution, @Receives, pub/sub vs unicast vs request-reply, and why Spring has no native equivalent.