Backend Developer

I work on the core transaction-processing platform for merchant acquiring, supporting high-volume and business-critical operations.

My work includes transaction-flow orchestration, risk assessment, payment-provider discovery, and state consistency through asynchronous integrations. I use DDD, CQRS, and event-driven architecture with an emphasis on scalability, observability, and resilience during traffic spikes.

I also collaborate with the Security team on manual vulnerability analysis to validate real-world risk in a regulated environment.

I worked on financial transaction-processing systems, including TED operations based on the FEBRABAN standard and PIX operations.

I maintained and evolved an application that read and processed transactional files, ensuring data consistency, integrity, and compliance with security requirements.

I applied secure-development practices, performed code analysis and PII protection validation, and identified and remediated a critical encryption-related vulnerability, including sanitization of previously processed records.

I contributed to a digital transformation initiative that modernized a legacy B2B platform. The platform evolved from a PHP system with business logic concentrated in PostgreSQL stored procedures into a solution with a Next.js frontend and Node.js/TypeScript APIs.

I participated in defining and adopting Clean Architecture, creating reference projects and delivering technical training on REST APIs and modern development practices.

I supported development teams, reviewed tests, standardized engineering practices, and analyzed critical application and infrastructure vulnerabilities to strengthen security.

I worked on the backend of an integration platform that enabled companies to create custom connectors.

I developed a Node.js API using NestJS, Express, and MongoDB, enabling execution of user-provided JavaScript through an internal SDK.

I implemented connector-lifecycle automation, including dynamic repository creation, versioning, and CI/CD pipelines for automated production deployments, with focus on isolation, scalability, and autonomous connector execution.

I held multiple roles including Security Analyst, Junior Web Developer, Implementation Specialist, and Technical Consultant.

As a Security Analyst, I led penetration testing, vulnerability analysis, technical reporting, internal training, and the development of vulnerability-detection tools aligned with the OWASP Top Ten 2017.

I also developed web applications, APIs, automations, and integrations; supported third-party system integrations; and provided technical support to developers using electronic document-processing components.

I participate in bug bounty programs and security research, identifying and reporting web application vulnerabilities for large organizations through responsible disclosure practices.

I perform technical analysis and digital investigations, including evidence correlation and analysis of data supplied by external platforms in support of legal proceedings.

I provide contracted security consulting, including full web application penetration tests, technical reports, remediation guidance, secure-development recommendations, and educational content for developer awareness.