👋 Hey there, I'm Matheus Oliveira!

Most Java developers know Quarkus. Few understand the Quarkus Way.

The Quarkus Way is more than using a framework. It is a shift in how you think about building Java applications: startup in milliseconds, minimal memory footprint, compile-time optimization, and developer joy through live reload. When you master this approach, you stop building Java apps the old way and start building software that is truly cloud native.

I help professional Java developers make that shift.

🔹 Open Source Contributions Across the Quarkus Ecosystem

• Quarkus LangChain4j — Built the @OnThinking annotation for reasoning output handlers, added named embedding store support across six databases (pgvector, Chroma, Milvus, Neo4j, Weaviate, Qdrant), introduced the Oracle embedding store extension, implemented audio transcription for OpenAI, added support for additional model options in Ollama, and enabled named OIDC clients in OidcClientMcpAuthProvider.
• Quarkus Roq & Qute Web — Enhanced the Roq Editor with SSH agent integration for secure git sync, and added GFM alert block support to the Qute Web markdown plugin.
• pt.quarkus.io — As maintainer of the Brazilian Portuguese translation, I fixed broken guides after upstream Web Components migration, improved contributor onboarding with CONTRIBUTING.md, and translated key documentation.
• Quarkus Core — Contributed Javadoc for build item documentation (ApplicationInfoBuildItem, AdditionalClassLoaderResourcesBuildItem).

🔹 Production Experience at Scale

AWS Certified and focused on cloud-native architectures. As a Software Engineer at BMW Group TechWorks Brasil powered by act digital, I build cloud-native applications with Quarkus, Angular, and AWS. My broader background includes Spring Boot, messaging (Kafka, RabbitMQ, SQS/SNS), and CI/CD automation.

🔹 From Music to Code

My path to software engineering was unconventional. Before code, I spent seven years as a music teacher, developing the analytical ear and collaborative discipline that now drive my work in agile teams. That background taught me something valuable: the best engineers, like the best musicians, are the ones who listen before they play.

If you are building with Quarkus, contributing to the ecosystem, or looking for someone who lives the Quarkus Way, let's connect.

📧 Get in touch: hi@omatheusmesmo.dev

I believe in the power of Open Source! Here are some projects where I've left my mark:

• quarkus-discord4j — Discord bot integration for Quarkus    🔗 My PRs
• quarkus-qute-web — Added GFM Alerts (admonition blocks) support to the Qute Web markdown plugin    🔗 My PRs
• LangChain4j — Upstream contributions to the LangChain4j framework    🔗 My PRs
• quarkus-openapi-generator — Hot deployment of OpenAPI files in dev mode    🔗 My PRs
• JNoSQL — Jakarta NoSQL framework for scalable Java apps    🔗 My PRs
• BuildCLI — Maintainer. Task automation tool for Java projects    🔗 My PRs
• Jakarta Servlet — Evolution of the Jakarta Servlet Specification    🔗 My PRs
• qlawkus — OpenClaw clone built with Quarkus LangChain4j: autonomous engineering agent    🔗 Repo
• awesomeyou — Highlighting the human side of Brazilian Open Source    🔗 My PRs

Writing about Java, cloud-native architectures, and open source

• Event-Driven on the Free Tier: OCI Notifications (ONS) as an Event Bus
  Discover how to implement Event-Driven Architecture on OCI Always Free using OCI Notifications (ONS). ONS delivers 1M HTTPS notifications/month and 1000 emails/month for free.

• Floci: a Free, Drop-in LocalStack Alternative Built on Quarkus
  LocalStack Community froze in March 2026 and now asks for an auth token. Floci is the no-strings-attached replacement: a free, MIT-licensed, Quarkus-native local AWS emulator. I test it for real: AWS CLI, a real Lambda, two ways of wiring a Quarkus app (Dev Services and Testcontainers), and a LocalStack migration.

• The Active Record Pattern and Hibernate Reactive: Entities That Save Themselves in Quarkus
  Entities that save themselves! Refactor your orders application to the Active Record pattern with PanacheEntity, learn when to choose Repository vs. Active Record, and enter the reactive world with Hibernate Reactive and @WithTransaction.

• AI Agent Tools in Quarkus LangChain4j: When the REST Client Becomes the LLM's Right Hand
  Build an AI agent that calls real REST APIs as tools, without writing any orchestration logic. REST Client + @Tool = automatic tool. The LLM decides when to call, which to call, and with what arguments. Everything runs locally with Ollama via Dev Services, zero API key.

• Persistence with Panache: From Spring Data JPA to the Repository Pattern in Quarkus
  No more in-memory lists! Evolve your orders application with real persistence using Hibernate ORM with Panache in the Repository pattern. Dev Services, pagination, HQL queries and the transition from Spring Data JPA.

🎯 Sharing insights and experiences at tech events and meetups.

• May, 2026 - ConexãoDevSquad: Tech Career Talk: How to Break Into the Industry
• April, 2026 - Brasil JUG: Getting Started with Quarkus Framework
• April, 2026 - Quarkus Club: *Contribute to Quarkus - Open your first PR
• September, 2025 - The Developers Conference: Open-Source: Standing out in your career through code (Mentorship)
• March, 2025 - SouJava JUG: BuildCLI: An Open-Source project worth knowing
• March, 2025 - BuildCLI Discord: New Member Onboarding Meeting

Here are some projects I built from scratch. Each one represents a different technical challenge and unique learnings!