I am a seasoned professional with extensive experience in software development and technical leadership, working on strategic projects for large-scale companies in the technology sector. With over a decade of expertise, I began my career as a Java developer in 2011, focusing on mobile development with J2ME and maintaining back-end applications. My professional growth led me to Android development and eventually to a senior developer role, mastering technologies like Java, Kotlin, and modern architectures.

Throughout my journey, I have had the opportunity to lead teams and influence strategic decisions, with key highlights including:

• Technical Leadership: As Tech Lead in the logistics vertical at Magazine Luiza, supporting squads in defining architectures, establishing patterns, and creating solutions that simplify development. Additionally, I contributed to complex cloud migration processes, including transitions between AWS, GCP, and MagaluCloud.
• Development and Automation: As a Back-End developer, I built and maintained critical systems, focusing on the automation and modernization of legacy systems, directly improving customer experience and operational efficiency.
• Infrastructure Optimization: Participated in cost-reduction and performance optimization projects, aligning infrastructure with sustainable business growth.

Currently, as a Staff Software Engineer in the Corporate Financial Services unit at PicPay, I hold a strategic and technical role, leading architectural decisions and driving scalable, resilient solutions. With a focus on transaction capture in the Acquiring sector, I leverage technologies like Spring Boot, RabbitMQ, Docker, AWS, etc, combined with observability tools like Grafana and Prometheus, to ensure high performance and stability.

Beyond technical development, I am committed to knowledge sharing by creating presentations and disseminating best practices, fostering consistency and excellence in team deliveries.

I am always seeking challenges that allow me to grow professionally and contribute to the success of the projects I engage with.

• Java (My main language) ❤️
• Kotlin (Loved language used to Android development)
• Python (Used to simplify scripts)
• C (IOT/Arduino hobby)
• GO (For knowledge of other paradigms)

• Descomplicando a Clean Architecture
• Pirâmide de Testes — Definindo uma boa suíte de testes para seu Software
• Java Garbage Collector — Por que precisamos conhecê-lo?
• Controlando transações de status com Finite State Machine
• Criando uma aplicação modular muito além do Clean Architecture
• Refatoração, a maneira mais eficiente de manter seu código limpo.
• Separando os testes integrados de sua aplicação em um novo conceito
• Observabilidade: Monitorando sua aplicação a partir de métricas
• O Core Domain: Modelando Domínios Ricos
• O Use Case: Modelando as Interações do Seu Domínio

• helpdeveloper/gzip-json-jackson - This library uses Jackson library to convert your POJO to a compressed JSON with GZIP.
• gbzarelli/chronometer-library - An Android library designed to make it easy to use a stopwatch with laps and a custom Widget to display the milliseconds.
• gbzarelli/AndroidFaceDetectOpenCV - Sample of the OpenCV in Android. Use the OpenCV SDK to detect faces natively.

• helpdeveloper/java-modular-architecture - Modular architecture with Java, base for some articles (About Architecture, About tests)
• gbzarelli/quaklog-api - Luizalabs challenge and created with an simplify Clean Architecture article.
• gbzarelli/fsm-devpira-2020 - Used to presentation about Finite State Machine in DevPira 2020 (Python Samples)
• helpdeveloper/java-observability-metrics - Used to presentation about Observability with Metrics

• gbzarelli/VelocimetroAlert - An app to use when I ride my bike with precisely measures
• gbzarelli/LapsCounter - Application for timing and counting laps in swimming/running/cycling.
• gbzarelli/VelocimetroAlertaBLModule - Hardware module building in Arduindo to use with my Speedometer Alert
• gbzarelli/wg-brew-plus - The project automates the mashing and boiling process of the craft beer manufacturing stages.

• gbzarelli/gophertalk - Multi-user chat in GO
• gbzarelli/githubers - Used to know new reactive features in Android (outdated)
• gbzarelli/hangman-python - Hangman Game in Python
• gbzarelli/clj-blackjack - Blackjack game in Clojure
• gbzarelli/events-distribution-platform - Architecture POC to Event Drive and Webhook

• https://helpdev.com.br
• https://www.linkedin.com/in/gbzarelli/
• https://twitter.com/gbzarelli
• https://medium.com/@guilherme.zarelli
• [email protected]