Junior Java Developer · Oct 2009 - Aug 2011

I helped migrate an ERP to JSF and RichFaces on JBoss with Hibernate JPA persistence, and built JasperReports exports for Excel, Word, PDF, and TXT. I developed a Java library that sent commands directly to parallel ports and interpreted output for major dot-matrix printers, as well as an export library for the Nota Fiscal Paulista tax program.

I designed and implemented a complete Brazilian electronic invoice (NF-e) library. It covered JAXB XML serialization, A1 and A3 digital certificates, XML signatures, issuer data, DANFE generation, SOAP government integrations, batch submission, status queries, cancellation, number invalidation, registration lookup, and contingency modes. The library was fully integrated into the ERP.

I also trained and supervised developers using JSF, RichFaces, and Hibernate, helping standardize implementation practices.

Junior Java Developer Intern · May 2009 - Sep 2009

I studied and prototyped persistence with JDBC and Firebird, then Hibernate JPA, Servlets, JSP, and JSF. I participated in evaluating the technology stack for migrating a legacy Delphi application, comparing user experience, hardware needs, scalability, and development productivity.