Quarkus

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.

Matheus Oliveira talking at an event about his open source journey

I Did It! Top 10 Contributor on Quarkus LangChain4j

An ordinary Monday morning, no stage and no audience, I found out I’d reached 10th place among the contributors to quarkus-langchain4j in the world. The story of how I got there in 5 months, and what changed along the way.

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.

One trace threading through five lanes, from browser to Angular, Java, .NET, Go and Node, over HTTP, gRPC and Kafka

Observability in Practice: Distributed Systems, Cost and Production

Part 2 of 2. One browser click crossing five systems and four languages in a single trace, and what changes when that goes to production: tail sampling, cardinality, exemplars and SLOs.

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.

Matheus Oliveira on the main stage at TDC Floripa 2026

Face to Face with Claude: I Got Pulled Onto the TDC Main Stage With No Warning

I almost didn’t go. The panel topic changed, my speaking partner couldn’t make it, and I hadn’t budgeted for the trip. Hours after arriving, the founder of the largest tech conference in Latin America called me onto the main stage in front of 200+ people. This is the interview where I explain how.