# Johanes Ferreira "Joe"

> Deep expertise in Java microservices and enterprise systems. Building full-stack applications with Rails and React. Creating AI workflows that shift engineering time from routine code to architecture and product thinking.

## About

Johanes Ferreira is a Senior Full-Stack Software Engineer based in Parana, Brazil, with over 16 years of experience delivering software solutions for organizations across Brazil, Portugal, France, South Korea, USA, Poland, and Spain.

He specializes in owning systems end to end, from architecture and database design to backend services, distributed processing, frontend delivery, and AI integration. His work focuses on turning complex, manual workflows into reliable, automated systems at scale.

His background spans Java, SOA architecture, and test automation, building a strong, practical understanding of the full software development lifecycle. Today, he applies that foundation to design and deliver complete, production-ready systems.

More recently, he has focused on AI-driven platforms, including multi-provider LLM extraction pipelines and development automation systems powered by specialized agents that handle routine tasks across the SDLC, freeing engineers to focus on architecture and product design.

## Availability

Johanes is an independent consultant available for hire. He accepts both project-based engagements (fixed scope, deliver and handoff) and ongoing retainers (monthly engagement, continuous improvement).

## Services

### AI Process Automation
Turn manual, repetitive workflows into reliable AI-powered systems. Document extraction, data processing, intelligent matching. Multi-provider LLM architecture with failover for reliability.

### Full-Stack Application Development
End-to-end systems from database design to production UI. Ruby on Rails, React/TypeScript, Java/Spring Boot. Multi-tenant SaaS, event-driven architectures, API design.

### AI Integration Consulting
Integrate OpenAI, Gemini, Claude, or OpenRouter into existing products. Prompt engineering, validation frameworks, cost optimization. Multi-provider strategies for reliability and performance.

### DevOps & CI/CD Automation
GitHub Actions, Docker, Kubernetes deployment pipelines. Automated testing, build optimization, monitoring. Developer workflow tooling that reduces friction.

## Contact

- Email: dev@johanes.com.br
- Website: https://johanes.com.br
- GitHub: https://github.com/johanes
- LinkedIn: https://www.linkedin.com/in/johanes-dev/
- Location: Parana, Brazil

## Skills

### Languages
Java, Ruby, JavaScript, TypeScript, Groovy

### Frameworks
Ruby on Rails, Spring Boot

### Cloud and DevOps
AWS, Azure, Docker, Kafka, Kubernetes, Sidekiq, Redis, GitHub Actions, Jenkins

### Databases
PostgreSQL, MySQL, MongoDB, Oracle

### AI and LLM
OpenAI API, Google Gemini API, OpenRouter, Claude Code, MCP Protocol

### Architectures
Microservices, Event-driven, Multi-tenant SaaS, SOA, Cloud-native, Twelve-Factor Apps

### Testing
BDD, TDD, JUnit, Cucumber, Minitest, Jest

### Security
Blue Security Champion, Secure Coding, Threat Modeling

## Spoken Languages

- Portuguese: Native
- English: Fluent
- Spanish: Fluent

## Experience

### SubBase (April 2025 - Present)
**Senior Full-Stack Software Engineer** - Remote

Full-stack engineer owning entire modules from database design to production UI on a construction procurement SaaS platform. Built an AI-powered development automation framework that handles routine coding tasks, shifting engineering time from boilerplate to architecture, code review, and product design.

- Owned and delivered the Concrete Commitments module end-to-end, the company's core pour management system handling scheduling, pricing, and logistics for construction projects
- Co-designed an AI document extraction framework that processes PDFs into structured data, replacing manual data entry and dramatically reducing processing time for delivery tickets, invoices, and quotes
- Built an AI automation framework that handles routine coding tasks, shifting engineering time to architecture, code review, and product design
- Designed an intelligent matching algorithm that automatically correlates extracted document data with existing records, eliminating hours of manual review per batch
- Improved document processing accuracy by implementing multi-provider AI with automatic failover, ensuring reliable extraction even when individual providers experience issues
- Integrated project management, version control, QA, and documentation tools into a unified developer workflow, reducing context-switching and accelerating delivery cycles

Technologies: Ruby on Rails, React, TypeScript, MobX, PostgreSQL, Sidekiq, Redis, OpenAI, Gemini, Claude Code, GitHub Actions, Ant Design, Material-UI

### ING Espana and Portugal (July 2023 - March 2025)
**Senior Software Engineer** - Madrid, Spain

Worked on mission-critical payment processing systems at one of Europe's largest banks. Earned the Blue Security Champion title after passing a rigorous security assessment, becoming a reference for secure software practices across the team.

- Built and maintained payment microservices that process real-time banking transactions for millions of customers
- Championed modern Java 21 practices across the team, organized training sessions that upskilled colleagues on functional programming
- Created real-time monitoring dashboards that gave the payment department full visibility into system health and performance
- Led build pipeline optimization with DevOps, significantly reducing development cycle times across the bank
- Earned Blue Security Champion certification, became the team's go-to person for secure coding practices and threat modeling

Technologies: Java, Spring Boot, Kafka, Prometheus, Grafana, Java 21

### EPAM Systems (September 2019 - June 2023)
**Senior Software Engineer in Test** - Katowice, Poland

Built internal tools and testing frameworks adopted across multiple projects at one of the world's largest IT consultancies. Became a reference for test automation and quality engineering practices.

- Created proprietary libraries used across multiple company projects for test data generation, became the standard tool for realistic test environments
- Designed testing frameworks that enabled teams to write and run automated tests in plain English, reducing the barrier for non-developers to contribute to quality
- Built CI/CD pipelines that automated the entire build-test-deploy cycle, cutting manual release effort significantly
- Authored technical guides and best practices adopted organization-wide, becoming a knowledge-sharing reference across teams

Technologies: Java, Spring Boot, Spring Cloud, Docker, Cucumber, Groovy, Jenkins, GitLab CI

### Wipro Limited (July 2017 - July 2019)
**Senior Software Engineer in Test** - Curitiba, Brazil

Contributed to the integration between Amazon Marketplace and Mastercard's global data platform, improving how financial institutions access corporate card transaction data for millions of users.

- Built test automation for the Amazon-Mastercard integration that validated transaction data accuracy across payment systems
- Delivered technical consulting and training across three countries (USA, India, Brazil), standardizing quality practices globally
- Streamlined testing strategies that reduced regression cycles and accelerated feature delivery to production

Technologies: Java, Spring Boot, REST APIs, BDD, API Testing

### FerreirApps (June 2016 - June 2017)
**Senior Java Software Engineer** - Pato Branco, Parana, Brazil

Founded a consulting practice, delivering software solutions for startups worldwide. Worked directly with founders to turn ideas into production-ready products.

- Delivered production-ready microservices and Android applications for international startup clients
- Worked directly with founders across multiple countries, translating business needs into scalable technical solutions
- Managed the full project lifecycle, from requirements gathering through deployment and handoff

Technologies: Java, Android, Microservices, Agile

### BRQ (November 2015 - April 2016)
**SOA Architect** - Curitiba, Brazil

Designed the integration architecture for a major telecommunications merger between GVT and Telefonica, ensuring millions of customers could be migrated seamlessly between systems.

- Designed the middleware architecture that connected disparate systems during the GVT-Telefonica merger, handling high transaction volumes
- Worked with business stakeholders to ensure technical decisions aligned with merger timelines and customer impact requirements

Technologies: Java, SOA, Web Services, Enterprise Integration

### Wipro (January 2015 - November 2015)
**Senior Java Software Engineer** - Curitiba, Brazil

Built middleware for Mastercard's payment processing systems, handling high-volume financial transactions that required strict performance and security standards.

- Developed high-volume, low-latency transaction systems processing real-time payment data for Mastercard
- Mentored new team members through workshops and training sessions, accelerating their onboarding
- Met stringent financial industry compliance requirements for performance, reliability, and data security

Technologies: Java, Middleware, Payment Processing, Financial Systems

### JTech Development (October 2013 - December 2014)
**Java Software Developer** - Sao Paulo, Brazil

Built Android mobile applications for clients, handling the full lifecycle from concept through Play Store deployment.

- Delivered mobile applications from concept to deployment, working directly with clients to refine requirements
- Optimized app performance to run smoothly across a wide range of Android devices and screen sizes

Technologies: Java, Android, Mobile Development, Client Consulting

### CISS Software (October 2011 - September 2013)
**Java Software Developer** - Dois Vizinhos, Brazil

Built server applications and integration services for an ERP platform used by Brazilian supermarkets for tax compliance and retail operations.

- Built integration services that connected the ERP platform with government tax systems, ensuring compliance for retail clients
- Developed web service clients that automated tax-related operations, replacing manual processes for supermarket chains

Technologies: Java, WSO2, SOA, Web Services, ERP

### Vietec (January 2010 - July 2011)
**Java Software Developer** - Pato Branco, Brazil

First professional role, built server applications for a dairy industry management platform, gaining hands-on experience across the full development stack.

- Built back-end services powering business operations for dairy industry clients
- Worked directly with industry stakeholders to understand domain challenges and translate them into software solutions

Technologies: Java, Google Web Toolkit (GWT), Server Development

## Education

- **Specialization in Java, Information Technology** - Universidade Tecnologica Federal do Parana (2011 - 2012)
- **Bachelor of Technology (B.Tech.), Information Technology** - Centro Universitario Mater Dei, Unimater (2006 - 2010)

## Certifications

- Blue Security Champions
- Docker for Developers
- Cloud Native Twelve-Factor Applications
- Advanced Spring: Spring Boot Actuator
- Threat Model for Blue Security Champions

## Honors

- Lisbon Challenge 2014 - Top #10

## Projects

### Concrete Commitments Platform (Active - SubBase)
End-to-end pour management module with AI-powered delivery ticket extraction, mix log matching, fee scheduling, and file attachments.
Technologies: Ruby on Rails, React, TypeScript, MobX, PostgreSQL, Sidekiq, OpenAI, Gemini

### AI-Powered Development Automation (Active - SubBase)
AI automation platform with 4 specialized agents (architecture planner, full-stack developer, QA tester, issue triage) that handles routine development tasks, freeing engineers to focus on architecture and product design. Includes a headless CI variant for GitHub Actions.
Technologies: Claude Code, MCP Protocol, Linear API, GitHub Actions, Qase, Shell

### Multi-Provider AI Extraction Pipeline (Active - SubBase)
Provider-agnostic LLM architecture with OpenAI/Gemini failover for automated document extraction across concrete delivery tickets, invoices, and quotes, with OCR integration and validation frameworks.
Technologies: Ruby on Rails, OpenAI API, Google Gemini API, Nanonet OCR, Sidekiq

### Payment Processing Microservices (Completed - ING)
Critical microservices for ING's payment systems with Kafka event-driven architecture.
Technologies: Java, Spring Boot, Kafka, Prometheus, Grafana

### BDD Test Automation Framework (Completed - EPAM Systems)
Proprietary Java libraries and Groovy-based BDD framework for microservices testing.
Technologies: Java, Groovy, Cucumber, Spring Boot, Docker

### Mastercard Integration Platform (Completed - Wipro Limited)
Amazon Marketplace integration with Mastercard's Global Data Repository.
Technologies: Java, Spring Boot, REST APIs, BDD

## Recommendations

"I had the pleasure of working with Johanes at SubBase, where he consistently demonstrated strong technical ability, thoughtful problem-solving, and a high level of ownership in their work specifically when it came to the underlying agentic system he was part of at SubBase. Johanes is the kind of engineer who not only executes well but also takes the time to understand the broader context of what he is building. He asks the right questions, communicates clearly, and collaborates effectively across teams. Whether it was tackling complex technical challenges or delivering under tight timelines, Johanes brought a level of reliability and professionalism that made a real impact." - Eric Helitzer, LEED AP, Founder and CEO of SubBase

"Johanes and I have been working together for almost two years, and in that time I have had the chance to know a great and fully committed person. He has developed his work with enthusiasm, always proposing ideas to make our work the best it can be, along with his outstanding commitment to the project and to getting things done." - Matias Nicolas Padilla Villalon, Product Owner and Product Manager

"Johanes is a very productive engineer, he did an exceptional job at helping the teams improving their test scenarios. Johanes is proactive, result oriented and certainly can get my full recommendation." - Jocelyn N'TAKPE, Head of Engineering and Architecture

"Successful software development is about possessing the right combination of expertise, attitude, and behaviors. As a manager of Johanes, I found working with him to be a personally rewarding experience. Johanes is eager to learn and refine his technical abilities while maintaining a positive outlook on tasks and deliverables. He handles complex assignments with little oversight and is not hesitant to recommend alternative approaches. Johanes adds immediate value to any software development team." - James Herrmann, Vice President, Security Solutions at Mastercard

"Johanes was an above-average student with great technical ability and an extraordinary ease in building relationships. During his specialization, he maintained his charisma and remarkable academic competence. Excellent student, excellent professional, and excellent person." - Omero Francisco Bertol, Professor, Universidade Tecnologica Federal do Parana