Welcome to my blog! 👋

I help professional Java developers master the ‘Quarkus Way’, empowering them to build high-performing apps and become highly valued engineers. Soli Deo Gloria!

16-bit SNES-style pixel art of a character walking through an open wooden gate, past a scribe's desk with a half-translated scroll, into a sunlit village square with a fountain, castle, and bridge in the background

Docs and Translation: The Easiest Way to Start Contributing to Open Source

Want to contribute to Open Source but freeze before you even open the editor? Documentation and translation are the easiest door in, and you can ship your first PR today.

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.

A slip-box of notes wired into an AI agent

Using Zettelkasten with Agents

How structured note-taking with Zettelkasten became the memory layer for my AI agents, and how it saves me tokens, time and money.

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.

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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.