John Sellis is a seasoned IT specialist with over two decades of experience in software development, analysis, architecture, and technical leadership. He boasts a comprehensive portfolio of proficiencies in technologies, including Java, JEE, EJB, JPA, Hibernate, RabbitMQ, and AMQP. John's skill set also extends to the development and integration of various technologies and frameworks, such as Spring Boot, Microservices, Domain-Driven Design, CQRS, SCRUM, and Kanban. He has a vast background in data administration, application tuning and queries, multithreading, and batch processes. John is also adept in using development tools and methodologies such as JUnit, Mockito, Maven, SVN, TDD, UML, and Jira, among others.

John pursued Pós Graduação em Engenharia de Componentes Java e WebServices and Superior Tecnólogo em Desenvolvimento de Sistemas, Tecnologia da Informação at FIAP. He also has an educational background in Information Technology at Instituto Brasileiro de Tecnologia Avançada - IBTA.

Throughout his career, John worked for well-known companies such as Zup Innovation, C6 Bank, 5A Attiva, CI&T, TOTVS, and Resource IT Solutions, among others. He has also used various relational databases, including Oracle, MySQL, SQLServer, PL-SQL, T-SQL, and NoSQL databases such as REDIS, MongoDB, and HazelCast.

John Sellis is a proficient IT specialist who continuously seeks to upskill to deliver the best IT solutions. With his extensive experience and expertise, John is an asset to any organization he works with.