Professional Experiences

Client: MedEspecialista

Period: August 2024 - Current

Situation

MedEspecialista, an educational platform for medical professionals, needed urgent improvements to enhance system performance, reliability, and maintainability. The existing system, built with Node.js and React, had infrastructure issues, lacked a CI/CD pipeline, has outdated libraries, and required new features to optimize user experience and operational efficiency.

Task

As the sole developer, I took full ownership of maintaining and modernizing the platform, addressing infrastructure challenges, implementing new functionalities, and improving system performance. The project required restructuring the Digital Ocean-based infrastructure, setting up a CI/CD pipeline, and developing new features while ensuring stability and scalability.

Action

• Reorganized repositories, recovering and structuring them after previous developers left the company.
• Revamped infrastructure, creating new Digital Ocean servers and implementing automated deployment scripts for staging and production.
• Implemented a CI/CD pipeline, streamlining deployments and reducing errors.
• Developed new functionalities, including: -- A monitoring and follow-up module, enabling tutors to track student progress and send automated email reports. This reduced processing time from one month to a single afternoon, optimizing workload and efficiency. -- A redesigned flexible study schedule module, replacing a basic pie chart system with an interactive, real-time progress tracker that provides study insights and time tracking. -- A visual schedule creation tool, allowing students to generate study plans with predefined subject weights, simplifying customization and improving user engagement. -- Updated and modernized the codebase, migrating legacy JavaScript code to TypeScript, improving type safety, maintainability, and overall system security. -- Enhanced UX/UI across multiple modules, implementing remote pagination, search functionalities, and a more intuitive admin dashboard. -- Implemented automated testing with Jest, improving system reliability.

Result

• Took over the responsabilities of two full-time developers, handling all necessary tasks - from requirement gathering with stakeholders to deployment - including infrastructure management, backend and frontend development, automated testing, bug fixing, and any other required tasks.
• Reduced system maintenance complexity, cutting deployment time and infrastructure issues significantly.
• Reduced the follow-up process time by 97% by automating processes that previously took four weeks, thereby increasing the tutors' efficiency and saving time and resources.
• Enhanced code quality, improving system scalability, maintainability, and user experience.

Client: Muvz

Period: November 2023 - April 2024

Situation

A major newspaper client needed to modernize its subscription and content management system, which was built using monolithic Java (EJB) services. The system was outdated, difficult to scale, and had high maintenance costs. Additionally, the client wanted to improve front-end performance and transition to a more efficient, event-driven communication system.

Compounding the challenge, the previous development team left the company, leaving only one remaining developer. To rebuild the team, the company assembled a new group of six developers—two mid-level and four junior developers—all of whom specialized in front-end development and had limited experience with Java.

Task

As the senior developer, I was responsible for:

• Designing the architecture for new microservices following Clean Architecture, Hexagonal Architecture, SOLID principles, and design patterns, creating a template project used as a foundation for other microservices.
• Migrating legacy monolithic services to a microservices architecture using Java 17, Spring Boot, and Apache Kafka.
• Enhancing the front-end applications to improve usability and performance.
• Introducing event-driven communication to replace some of the existing synchronous REST calls.
• Setting up a Kafka test cluster using Docker Compose, enabling developers to run local tests and providing the DevOps team with a starting point for configuring Kafka in Kubernetes.
• Mentoring the team on modern development practices to improve code quality and team efficiency.

Action

• Developed and deployed 5 microservices, leveraging Spring Boot, Spring Security, Spring Data JPA, Spring Cloud OpenFeign, MapStruct, Lombok, and Kafka, enabling better system modularity and reducing interdependencies.
• Refactored the front-end applications, implementing React, Next.js, React Admin, React Hook Form, TanStack Query, and MUI, which significantly improved the user experience and responsiveness.
• Designed and implemented an event-driven architecture using Kafka, replacing synchronous service-to-service communication, improving performance, and reducing system latency.
• Created a centralized back-office system with Spring Boot and React Admin, allowing administrators to manage configurations, users, and subscriptions efficiently.
• Developed an email microservice integrated with Kafka for asynchronous email processing, including logging and auditing capabilities to ensure message traceability.
• Collaborated with DevOps to deploy the system on Kubernetes, creating a robust CI/CD pipeline for automated deployments and system monitoring.
• Led mentorship and training sessions on Hexagonal Architecture, SOLID principles, and DDD, ensuring that the development team could maintain high-quality standards and optimize software development processes.

Result

• Successfully modernized the system, transitioning from a monolithic EJB-based application to a microservices architecture, reducing maintenance costs and improving system scalability.
• Improved system performance by over 40%, with faster response times and lower latency.
• Recovered an initial 3-month project delay, ensuring on-time delivery of all planned features.
• Empowered the team with modern software engineering practices, enhancing productivity and collaboration.

Situation

I joined Conddiz as a Senior Full Stack Developer to support a presidential campaign focused on increasing voter engagement and candidate visibility. The candidate had limited prior exposure, requiring an innovative digital strategy to differentiate them from leading opponents. This involved developing and maintaining a complex ecosystem of applications integrated with an existing backend system based on NodeJS and Strapi.

Task

My primary responsibility was to lead the development of three key applications – a campaign website, a gamified video app, and an interactive TV app – ensuring their functionality, scalability, and alignment with the campaign's goal of maximizing voter engagement. I was also tasked with mentoring junior developers unfamiliar with key technologies.

Action

Analyzed and implemented the backend system using NodeJS and Strapi, overcoming challenges related to content management integration.

• Developed three front-end applications using NextJS, MUI, ReactQuery, ReactHookForms, Yup, and next-seo:
  • Campaign Website: Developed a high-performance website providing comprehensive information about the candidate and campaign events, optimized for SEO and user experience.
  • Gamified Video App: Created an engaging video app allowing users to access and share campaign videos and playlists, leveraging gamification to increase user interaction.
  • Interactive TV App: Built a TV app with three modes – live streaming with YouTube chat integration, live election ad broadcasts with links to the official website, and on-demand access to recorded programs with a Twitter timeline.
• Mentored three junior developers with no prior experience in NextJS, providing training on core concepts like dynamic routes and static site generation, and guiding them through integration with Strapi and MUI.

Result

Successfully delivered all three applications on time and within budget, contributing to a significant increase in voter engagement. The campaign website received over 2 million visits with an average of 25,000 daily visitors, and with a peak of over 200,000 simultaneous accesses, the gamified video app was downloaded over 10,000 times, and the interactive TV app attracted over 10,000 viewers to live and on-demand programs. My mentorship enabled the junior developers to become proficient in NextJS and contribute effectively to the project.

Situation

I joined Digidados as a Software Architect for a critical project: the development of a comprehensive Condominium Management System. This system aimed to serve three key user groups – the property management team (managing approximately 400 condominiums in Uberlândia, Brazil), condominium residents, and condominium syndics – each with unique needs and complexities.

Task

My primary responsibility was to define and oversee the implementation of the system architecture, ensuring it met the diverse requirements of these user groups. This included gathering requirements, designing a scalable and customizable system, and mentoring the development team.

Action

• Gathered and analyzed requirements from users and the Project Owner, understanding the specific needs of different condominium types and user roles.
• Designed a monolithic architecture with a clear separation between backend (Java and Spring Boot, utilizing JHipster for code generation) and frontend (AngularJS) to simplify development and maintenance while ensuring seamless integration.
• Coordinated the development team using SCRUM methodologies, conducting regular planning, review, and retrospective meetings to maintain alignment and track progress.
• Mentored the team through pair programming, code reviews, and bi-weekly tech talks, fostering collaboration and knowledge sharing.
• Provided targeted training and mentorship to developers struggling with the project, creating personalized learning path with study materials, practice projects, and regular presentations to build confidence and technical skills.

Result

The implementation of the incident management system reduced the average response time from 5 days to 1 business day, significantly improving customer satisfaction. The automated invoice generation system reduced processing time from 2 days to 3 minutes, eliminating manual errors and improving communication. The successful delivery of the system architecture enabled the company to efficiently manage a large portfolio of condominiums and provide a valuable service to residents and syndics.

• Developed a printing management service for the Sankhya ERP, replacing the previous service based on Java Applets (a discontinued technology). The new service was implemented in Java 8, Guice, and JUnit (for testing), with the front-end developed in Adobe Flex and communication via REST.
• Contributed to Sankhya ERP improvements using Java 7, EJB, JSP, Oracle PL\SQL, SQL Server PL\SQL, GWT, Adobe Flex, Jboss, Widfly, and Jekins.

• Worked with a focus on system architecture, allocated at the Buscapé client and internal TQI projects, using technologies such as Java (SE and EE), Spring ecosystem, PHP, HTML, MySQL, Oracle, and JQuery

• I worked on various projects involving Java, PHP, HTML, and Javascript, as well as database technologies such as MySQL, Oracle, and PL/SQL. I also contributed to the implementation of software development processes based on CMMI 3 and mentored less experienced team members. Additionally, I worked on a proof of concept for integrating Flex and Java for Telefônica's back-office system.

• I worked on several projects, including a SQL execution audit system for Oracle databases using Logminer, performance evaluation for Hewitt using Struts 2, Spring and Hibernate, and a billing system using JSP, Servlets, and Hibernate. Other activities included modeling requirements and use cases with Enterprise Architect, and giving talks and training on Java SE and EE using Netbeans. Technologies used included Java, Struts, Spring, Hibernate, JSP, Servlets, and Enterprise Architect.

• I coordinated and instructed training programs including a Programming Formation Course (CFP) with 40 participants, where 31 were approved, and a Logic Programming course with 13 approved out of 40. I also coordinated a Java Advanced and Java for WEB training for five students, who were all hired. Additionally, I implemented tools to improve the development processes and organized mini-courses to enhance knowledge in various Java-related topics.

• I taught two courses: Introduction to Java Language and Applied Programming Logic in Java. Both courses lasted 40 hours and were successful, with 8 and 10 participants respectively. The Introduction to Java Language course covered the initial concepts of Java technology, and the Applied Programming Logic in Java course covered programming logic concepts using the Java language.

• I created two systems: the Research and Graduate Pro-Rectorate Management System, using Linux, Apache, MySQL, and PHP to manage research projects, and the Curriculum Lattes Analysis System, using Java to extract data from professors' curricula vitae.

• I developed a web interface for the Bioinformatics Laboratory, using Java SE and Java EE, Servlets, and JSP, along with Netbeans, XML, XSTL, and XPath. The interface integrated various laboratory systems and automated the processing of genetic sequencing data.

• I worked in the development of an automated testing system for hardware and multimedia in the assembly line of Novadata computers using Java SE. My responsibilities included analyzing, designing, and coding components for the system.