Portrait of Renato Garcia

Renato Garcia

Software Architect & Tech Lead

I design and run the distributed systems that keep e-commerce platforms and marketplaces in sync — millions of product, price, stock and order events a day.

Londrina, Brazil

Java Kotlin Quarkus Apache Kafka Kubernetes AWS
Read the work
20+ Years in software engineering
30+ Marketplace integrations live
10 Professional certifications

About

Software architect with 20+ years in production systems, most of it spent on integration: making systems that were never designed to talk to each other exchange data reliably, at volume, without losing an order. At GuBee I have owned the architecture since day one — a hub that connects e-commerce platforms to more than 30 Brazilian marketplaces — and I lead the engineering team that builds it.

Designed and still evolve an event-driven integration hub on Apache Kafka, built with microservices, Hexagonal Architecture and TDD

Deep in the JVM: Java, Kotlin, Quarkus and Spring Boot, deployed on AWS and Kubernetes

Track record across e-commerce, telecom, banking, credit and public sector — as architect, tech lead and consultant

20+ Years of experience
30+ Marketplace channels
10 Certifications
5+ Industries served

Experience

Software Architect

GuBee Full-time · Londrina, PR

Current role

Jul 2019 – Present

  • Own the architecture of an integration hub connecting e-commerce platforms to 30+ marketplaces, built on microservices and Test-Driven Development
  • Designed the event-driven backbone on Apache Kafka, with Redis and MongoDB for state and caching
  • Leading the migration to Quarkus native on AWS and Kubernetes, cutting service memory footprint by over 60%
  • Grew and lead the engineering team; set the standards for Hexagonal Architecture, DDD and automated testing
Java 21 Kotlin Quarkus Spring Boot Apache Kafka Kubernetes

Context

GuBee is a SaaS integration hub that connects e-commerce platforms (VTEX, Shopify, WooCommerce, Magento) to the major Brazilian marketplaces (Mercado Livre, Amazon, Magalu, Shopee and 30+ others). I have been the architect since the company's inception: I designed the distributed system from scratch and have been evolving it ever since, alongside a growing engineering team.

Responsibilities

  • Design and maintain the microservices architecture handling millions of daily product, order and stock synchronisation events
  • Define and enforce engineering standards across all services: Hexagonal Architecture, Domain-Driven Design, Test-Driven Development
  • Lead the migration from Spring Boot to Quarkus native, reducing memory footprint and cold-start times
  • Architect event-driven pipelines on Apache Kafka for real-time marketplace synchronisation
  • Mentor developers, own the technical backlog and drive product decisions with the business
  • Run the infrastructure: AWS EKS, Redis clusters, MongoDB Atlas

Stack

Java 21 Kotlin Quarkus Spring Boot Apache Kafka Redis MongoDB AWS EKS AWS Lambda Kubernetes Docker GitLab CI Hexagonal Architecture DDD TDD

Impact

  • Built the platform from zero; it now processes millions of integration events a day across 30+ marketplace channels
  • Quarkus native migration cut service memory usage by over 60%
  • Event-driven design holds product, order and stock sync at sub-second latency
  • Established the engineering culture: DDD, Hexagonal Architecture and automated testing as the default

Tech Lead

Serasa Experian Contract · Remote

Concurrent engagement

Jan 2025 – May 2025

  • Technical lead of the biometrics platform team: defined the architecture and owned delivery quality
  • Ran technical alignment and requirements refinement with product and business stakeholders
  • Built microservices and asynchronous flows on AWS SQS/SNS for biometric data processing
Java Spring Boot AWS SQS/SNS Oracle Autonomous DB Microservices

Context

Serasa Experian is Brazil's largest credit bureau. I joined the Biometrics Product team as Tech Lead, on a five-month contract running alongside my role at GuBee. The team owns the platform that handles identity verification through biometric data — a critical product in Brazil's digital identity ecosystem.

Responsibilities

  • Lead the team building the biometrics verification platform used by financial institutions and fintechs
  • Define system architecture and hold the quality bar across the microservices
  • Run technical alignment and requirements refinement sessions with product and business stakeholders
  • Translate complex business requirements into viable, scalable technical solutions
  • Design asynchronous messaging flows on AWS SQS/SNS for biometric data ingestion and processing

Stack

Java Spring Boot AWS SQS AWS SNS Oracle Autonomous Database Microservices REST APIs Docker

Impact

  • Contributed to one of Brazil's most critical identity verification platforms, serving millions of biometric checks
  • Bridged technical and business teams, turning stakeholder needs into well-defined engineering work

System Architect

Atos Londrina / São Paulo

Dec 2014 – Jul 2019

  • Architect on enterprise integration programmes for NET/Claro, Multiplus Fidelidade and Carrefour
  • Specialised in Oracle SOA Suite middleware, building OSB, BPEL and BPM interfaces to EAI patterns
  • Led the product definition for Carrefour's HeavyGoods platform, built on event-based microservices
Oracle SOA Suite OSB BPEL Java Microservices EAI

Context

Atos is a global IT services company. Across nearly five years I worked as a system architect embedded in major enterprise clients — NET/Claro in telecom, Multiplus Fidelidade in loyalty, Carrefour in retail. The role combined architecture definition, team leadership, technical proposals and hands-on integration work on Oracle's enterprise middleware stack.

Responsibilities

  • Define system architecture and lead development on large-scale enterprise integration projects
  • Write technical and commercial proposals, and defend the solution in client sessions
  • Design and implement OSB, BPEL and BPM interfaces following VETO and Enterprise Application Integration practice
  • Lead cross-functional teams across several client engagements at once
  • Drive Carrefour's HeavyGoods product definition, improving usability and sales conversion through event-based microservices

Stack

Java Oracle SOA Suite Oracle Service Bus (OSB) BPEL BPM Microservices EAI Patterns REST / SOAP Oracle Database

Impact

  • Served as the reference architect for three of Brazil's largest enterprise clients simultaneously
  • Carrefour HeavyGoods raised online sales conversion through a tool-driven, event-based architecture
  • Built the Enterprise Integration Patterns depth that later shaped the event-driven design at GuBee

Software Architect & Project Lead

Infracommerce Consultant · Greater Londrina

Nov 2013 – Nov 2014

  • Led projects on the ACEC e-commerce platform for Carrefour Group, Decathlon and Lança Perfume
  • Built a service-oriented architecture with separate administration, sales and ERP integration layers
  • Implemented Drools for dynamic pricing rules and Lucene/Solr for search and product discovery
Java Oracle ADF JSF BPEL OSB Drools

Context

Infracommerce is one of Brazil's leading full-service e-commerce operators. I joined as project leader and software architect for ACEC — a white-label e-commerce platform powering major retail brands, built on a service-oriented architecture with clearly separated layers for administration, sales and ERP/legacy integration.

Responsibilities

  • Lead development and architecture for the ACEC platform serving Carrefour Group, Decathlon and Lança Perfume
  • Design the administration layer in Oracle ADF for deal management, customer registration and product maintenance
  • Optimise the sales layer with REST APIs, JSF and Lucene/Solr for search and product discovery
  • Implement a Drools rules engine for dynamic pricing and promotion rules
  • Build the integration layer with BPEL and OSB services exchanging data with client ERPs

Stack

Java Oracle ADF JSF Solr / Lucene Drools BPEL OSB Oracle Database REST SOAP

Impact

  • Platform served some of Brazil's largest retail brands under high-traffic e-commerce operations
  • The Drools engine let non-technical teams manage dynamic pricing without code changes
  • Solr-powered search measurably improved product discovery and conversion

Tech Lead

Accurate Londrina / São Paulo

Aug 2010 – Nov 2014

  • Team lead on CPQD projects delivering city administration systems for the public sector
  • Owned requirements analysis, function-point estimation, architecture definition and team coordination
Java Architecture Function Points Team Leadership

Context

Accurate was a software consultancy later acquired by Infracommerce. I led development teams on government projects for CPQD, one of Brazil's largest telecom R&D centres, building city administration systems. The role sharpened my requirements engineering, estimation and team leadership.

Responsibilities

  • Lead the development team on public-sector systems projects
  • Gather and analyse customer requirements, translating them into technical specifications
  • Estimate project scope using Function Point Analysis
  • Define system architecture and technology stack for each project
  • Coordinate development activities and hold the delivery quality bar

Impact

  • Delivered multiple city administration systems for CPQD
  • Built the estimation and requirements-engineering competency that carried through the rest of my career

System Architect

Atos Embedded at Serasa · São Paulo

Jun 2013 – Nov 2013

  • Architecture definition and technical specification for credit applications, embedded in Serasa's engineering teams
Java Architecture Credit Systems

Context

A short engagement at Atos embedded within Serasa (now Serasa Experian), Brazil's largest credit bureau. My first exposure to the financial data and credit scoring domain, twelve years before returning to Serasa as a Tech Lead in 2025.

Responsibilities

  • Define system architecture for credit-related applications
  • Produce technical specifications and architecture documentation
  • Work with Serasa's internal engineering teams on integration points

Tech Lead

LINT Londrina

Jun 2009 – Nov 2010

  • Led development of a city administration system for CPQD, end to end
  • Owned customer requirements, architecture definition and team coordination through every project phase
Java Team Leadership Architecture

Context

LINT was a Londrina software house where I served as Tech Lead on government projects. The main engagement was a comprehensive city administration system for CPQD, managed across the full project lifecycle from requirements through delivery.

Responsibilities

  • Lead the development team through every phase of the CPQD city administration project
  • Gather and document customer requirements
  • Estimate project scope using function point analysis
  • Define system architecture and guide the team through implementation

Systems Analyst

Amadeus IT Group Travel & tourism technology

2008

  • Built insurance applications and a tourism platform project for Carrefour
  • Worked across the Java EE stack of the era: Struts 2, EJB3, JPA, Spring, Maven and web services
Java Struts 2 EJB3 JPA Spring

Context

Amadeus IT Group is a global technology company serving the travel and tourism industry. The role deepened my grounding in requirements definition, architecture design and Java enterprise development.

Responsibilities

  • Develop insurance applications using enterprise Java technologies
  • Contribute to a tourism platform project for Carrefour
  • Design and implement REST and SOAP web services for system integration

Stack

Java Struts 2.0 EJB3 JPA Spring Maven Web Services

Team Leader & Quality Assurance

BSI Tecnologia Banking systems · São Paulo

2003 – 2008

  • Started as a developer and grew into team leader and quality assurance over five years
  • Delivered projects for Itaú and Bradesco, integrating Java applications with mainframe Cobol systems
Java EJB2 Struts Hibernate Cobol

Context

BSI Tecnologia was a São Paulo software company specialised in financial sector applications. This is where my career began — from junior developer to team leadership and quality assurance over five years working with some of Brazil's largest banks.

Responsibilities

  • Develop and maintain Java applications for Itaú and Bradesco banking systems
  • Integrate Java applications with mainframe Cobol legacy systems
  • Lead development teams on banking project deliveries
  • Establish quality assurance processes and run code reviews

Stack

Java EJB2 Struts Hibernate Cobol Integration Oracle Database Mainframe

Impact

  • Progressed from junior developer to team leader and QA within the same company
  • Built the financial systems and enterprise Java foundation the rest of my career rests on
  • Gained rare experience integrating modern Java with mainframe Cobol — a scarce skill in banking

Stack

Core

Used daily in production

Java Kotlin Quarkus Spring Boot Apache Kafka Microservices REST APIs DDD Hexagonal Architecture TDD

Cloud & delivery

Where it runs and how it ships

AWS Kubernetes Docker AWS EKS AWS Lambda AWS SQS/SNS GitLab CI Linux

Data & integration

Storage and enterprise middleware

MongoDB Redis PostgreSQL Oracle Database Oracle SOA Suite OSB / BPEL Solr Drools

Credentials

Sun Certified Enterprise Architect

Sun Microsystems · 2010

Oracle Certified Professional, Java SE 7

Oracle · 2014

Professional Scrum Master I

Scrum.org · 2018

Also certified

Oracle SOA Suite 11g EssentialsOracle

2015

ITIL Foundation CertificateIT service management

2013

Sun Certified Associate, Java PlatformSun Microsystems

2008

Sun Certified Business Component Developer, Java EE 5Sun Microsystems

2007

Sun Certified Business Component Developer, Java EE 1.3Sun Microsystems

2007

Sun Certified Web Component DeveloperSun Microsystems

2006

Sun Certified Programmer, Java PlatformSun Microsystems

2006

Languages

Portuguese Native
English Upper-intermediate — CEFR B2 EF Level 12, EF Education First, 2017

Education

Postgraduate, Computer Software Engineering

Unifil — Centro Universitário Filadélfia

2014 – 2015

Bachelor of Science, Information Systems

Universidade Tecnológica Federal do Paraná (UTFPR)

2003 – 2007

renatojava.github.io · Full profile, project detail and contact links online.

Get in touch

Open to conversations about architecture, distributed systems and senior engineering roles.

renato.java@gmail.com +55 43 99639-9184 LinkedIn GitHub