Java backend
REST, GraphQL and SOAP APIs in Java 21 and Spring Boot 3, with Spring Security, JPA and messaging-oriented architecture.
— Hello, I'm
Ronny Arruda
Senior Java Developer|
I have been building mid- to large-scale enterprise systems for over 12 years, from the Java backend to the Angular interface. Robust backends, secure integrations and code that ages well.
Open to opportunities
Java 21
Spring Boot
Angular
Docker
About me
Systems that hold up
in the real world
I have been in the field since 2013, with over 12 years across the full lifecycle of enterprise systems and a solid track record in the Brazilian public sector. I deliver end to end: a backend in Java 21 and Spring Boot 3 with GraphQL, REST and SOAP, a frontend in Angular 19 with TypeScript and NgRx, and integration through messaging, caching and search.
I work a lot with security and authentication — Keycloak, OAuth2/OIDC and Gov.br — digital signatures and document generation, plus infrastructure and DevOps. I often take on legacy systems and lead the modernisation: migrating Java and Spring versions, rewriting services, and bringing tests along.
12+
Years of experience
30+
Enterprise systems
9
Companies and agencies
- Name Ronny de Arruda Pinho e Silva
- Email ronnyapinho@gmail.com
- Location Santa Catarina, Brazil
- Education BSc in Computer Science — UNIP
- Languages Portuguese (native), English (basic / technical reading)
What I do
How I can help
Angular frontend
Interfaces in Angular 19 with TypeScript, NgRx and RxJS, consuming GraphQL through Apollo and REST documented with OpenAPI.
Architecture and modernisation
Java and Spring version migrations, service rewrites, domain-driven design and expanded test coverage.
Security and digital signature
Keycloak, OAuth2/OIDC and Gov.br; PAdES, CAdES and XAdES signing and documents compliant with the Brazilian ICP-Brasil standards.
My expertise
Skills & technologies
Java
Spring
Angular
TypeScript
GraphQL
Oracle
PostgreSQL
Redis
RabbitMQ
Solr
Docker
Jenkins
Keycloak
Nginx
Git
Portfolio
Some of my projects
Spring AI MCP Brasil
MCP server with Spring AI
Gives AI assistants access to Brazilian public data: DataJud/CNJ court cases, company registry (CNPJ), postal codes and national holidays, with official data instead of guesses.
Medida Protetiva Online
Civil Judicial Police of MT
A platform that lets domestic violence victims request a protective order over the internet, through the website or the SOS Mulher app. Built by a team, live since March 2021.
Institutional project — source code is not public.
CuidaJá
Caregiver platform
Connects families to caregivers and nursing professionals: self-registration with nursing-council verification, city-first matching and a proposal funnel with fill rate and response time metrics.
GovBR Signature Integration
Digital signature
An API that signs PDFs with the Brazilian gov.br electronic signature, straight through the ITI signing API, one file at a time or in batches.
Quarkus GraphQL
Example application
A hands-on example of a GraphQL API built with Quarkus, covering the schema, the resolvers and the framework's native build.
Track record
Professional experience
2025 — Jul 2026
Backend Java Developer (contractor)
Poupex
Credit portability system with end-to-end integration into the CIP/ACTC ecosystem, covering 10 ACTC/ARQ file types. Full migration of file receipt and dispatch to CIP's official JAXB model, spanning the API, processing jobs and the legacy system.
Modernised the stack to Java 21, Spring Boot 3.5 and Spring Cloud 2025, reorganised around domain-aggregate design, standardised queries with JPA Specifications and expanded test coverage.
2023 — 2025
Full-Stack Developer
Public Prosecutor's Office of Mato Grosso
Around 30 enterprise systems: backend in Spring Boot 3 and Java 21, frontend in Angular 19 with NgRx. GraphQL APIs (Netflix DGS) and REST documented with OpenAPI, consumed through Apollo Angular. Security and SSO with Keycloak, Gov.br authentication and migration from Atlassian Crowd to OIDC.
Digital signers with BRy Framework and Gov.br, reporting with JasperReports in a microservice consuming RabbitMQ, search with Apache Solr, Redis caching and DevOps with Docker, Jenkins, Nginx, Kong and observability through Prometheus and Graylog.
2021 — 2023
Full-Stack Developer
Civil Judicial Police of Mato Grosso
Two stints, with a backend in Spring Boot and Quarkus and a frontend in Angular. Consuming and sending data over Web Services and Web APIs, JWT and Spring Security authentication, automated deployment via GitLab CI and a PostgreSQL database. The Medida Protetiva Online platform comes from this period.
May 2022 — Jun 2022
Backend Java Developer
Globalweb Corp
Backend development with Java and Spring Boot.
Nov 2021 — Apr 2022
Java Developer
Grupo GFT
Backend with Spring Boot, version control with Git/Bitbucket and continuous integration with Jenkins. Firestore and Elasticsearch data stores.
Aug 2019 — Mar 2021
Systems Developer
Public Prosecutor's Office of Mato Grosso
The SIMP3 project, working across backend and frontend. Spring Boot with GraphQL, frontend in Angular, Oracle database and Spring Security. Deployment with Bamboo, task management in Jira and Confluence.
Jan 2020 — Feb 2021
Front-end Developer (freelance)
AGRiTi
Built the id-cotton system on the frontend team, in Angular 8.
May 2017 — May 2019
Mid-level Java Programmer
Ábaco Tecnologia de Informação
Backend with JSF2, JPA/Hibernate and Bean Validation on WildFly 10 and Oracle; JWT and Spring Security; Git/GitLab and SVN; deployment with Jenkins.
Jun 2016 — Dec 2016
Junior Java Programmer
Vector Informática
Backend with TotalCross and JPA/Hibernate on WildFly 10 and an Oracle database.
Aug 2015 — Jul 2016
Web Development Intern
Regional Electoral Court of Mato Grosso
Backend with JSF 2.0, EJB 3.1, JAX-RS/RESTful, CDI and Maven; frontend in AngularJS and Bootstrap; Oracle 11g database.
Get in touch
Let's build something together
Got a project in mind, or a role that fits? Tell me what you need — I reply quickly.