Cassio L. Freires Souza

Backend Software Engineer with solid experience in developing, architecting and maintaining mission-critical enterprise systems. Specialized in building microservices, AI-powered solutions and high-availability APIs with C#/.NET, Node.js (NestJS) and Google Cloud Platform. Strong command of Clean Architecture, DDD, event-driven architectures and integration of complex ecosystems (JD Edwards ERP, Oracle Cloud, Salesforce), focused on scalable multitenant solutions, cutting proprietary-license costs and streamlining delivery through CI/CD.

Professional experience

Software Developer

  • Corporate NPS platform (in-house, multitenant): architected and led the end-to-end development of the proprietary platform that replaced a costly market tool, generating significant savings for the organization.
  • Designed it under Clean Architecture, DDD and SDD with NestJS, TypeScript, PostgreSQL and Redis, supporting multiple shopping centers and concurrent access.
  • Implemented concurrency, atomicity, idempotency, retry policies and Redis caching to guarantee consistency and performance.
  • Provisioned scalable infrastructure on Google Cloud Platform (Cloud Tasks, Load Balancers) with Terraform (IaC).
  • AFA tax ecosystem: designed the architecture that automates tax-obligation filing (REINF, EFD, ECF), removing manual entries at the Federal Revenue portal — SOAP API with the JD Edwards ERP, a NestJS REST API and a React admin panel, with pub/sub messaging.
  • Set up CI/CD pipelines (GitHub Actions + Docker) and lead code reviews, technical mentoring and best-practice adoption.

Systems Analyst

  • Maintained and evolved integrations between ERPs (Oracle Cloud, JD Edwards) and CRM (Salesforce) supporting the financial operations of multiple properties.
  • Automated operational flows and billing routines, reducing manual work and improving business teams' response time.
  • Optimized complex SQL queries and stored procedures, increasing billing-processing performance.
  • Handled high-priority incidents with strict SLA compliance.
  • Promoted to Software Developer for results in automation and in-house engineering.

Technical skills

C#TypeScriptJavaScriptSQL
.NET Core / ASP.NETNode.jsNestJSRESTSOAPRabbitMQ
Clean ArchitectureDDDEvent-DrivenMicroservicesSOLIDTDDMultitenancy
PostgreSQLRedisMySQLMongoDBRelational modeling
Google Cloud (GCP)TerraformDockerCI/CD (GitHub Actions)
JWTOAuth2RBACLLMsPrompt EngineeringSpec-Driven Dev

Education

B.Sc. in Electrical Engineering

Technologist in Systems Analysis and Development

Languages

  • Portuguese: Native
  • English: Technical / Intermediate