Engineering rigor applied to backend software.

I'm a Backend Software Engineer with experience developing, architecting and maintaining mission-critical enterprise systems. I build microservices, integrations and high-availability APIs in C#/.NET and Node.js (NestJS), applying Clean Architecture, DDD and event-driven architectures on Google Cloud Platform.

My path started maintaining integrations between ERPs (Oracle Cloud, JD Edwards) and CRM (Salesforce) and evolved into designing scalable multitenant platforms — such as an in-house NPS system that replaced a costly market tool. In parallel, I study Electrical Engineering, which reinforces the systemic perspective I bring to every architectural decision.

Profile photo of Cassio Souza
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Selected work

In-house NPS platform (multitenant)

Architected and led the end-to-end development of a proprietary NPS platform that replaced a costly market tool. NestJS + PostgreSQL + Redis, with concurrency, idempotency, retry policies and caching, on GCP provisioned via Terraform.

NestJSPostgreSQLRedisGCPTerraform

AFA tax ecosystem

Designed the architecture that automates tax-obligation filing (REINF, EFD, ECF), removing manual entries at the Federal Revenue portal. SOAP API integrating the JD Edwards ERP, a REST API in NestJS and a React admin panel, with pub/sub messaging for the async status of invoices.

NestJSSOAP/JDEPostgreSQLReactPub/Sub

Enterprise ERP/CRM integrations

Maintenance and evolution of integrations between Oracle Cloud, JD Edwards and Salesforce for the financial operations of multiple properties, with billing automation and SQL procedure optimization.

Oracle CloudJD EdwardsSalesforceT-SQL

Engineering culture

Built CI/CD pipelines with GitHub Actions and Docker for automated deploys, and lead code reviews, technical mentoring and the adoption of best practices (SOLID, Clean Code, automated testing).

CI/CDDockerCode ReviewMentoring

Timeline

Software Developer

End-to-end architecture and development of multitenant platforms (in-house NPS, AFA tax ecosystem), GCP infrastructure with Terraform and an engineering culture — CI/CD, code review and technical mentoring.

Systems Analyst

Maintenance and evolution of integrations between ERPs (Oracle Cloud, JD Edwards) and CRM (Salesforce), automation of billing routines and SQL query optimization. Promoted to Developer for results in automation and in-house engineering.

B.Sc. in Electrical Engineering

Theoretical grounding in power systems, electronics and control — reinforcing the systemic perspective I bring to software architecture.

Technologist in Systems Analysis and Development

Foundation in software engineering, algorithms and system architecture.

Tech stack

LANGUAGES

C#TypeScriptJavaScriptSQL

BACKEND & APIS

.NET / ASP.NETNode.jsNestJSRESTSOAPRabbitMQ

ARCHITECTURE

Clean ArchitectureDDDEvent-DrivenMicroservicesSOLIDTDD

DATA & PERFORMANCE

PostgreSQLRedisMySQLMongoDB

CLOUD & DEVOPS

Google Cloud (GCP)Terraform (IaC)DockerCI/CD (GitHub Actions)

APPLIED AI

LLMsPrompt EngineeringAgents / automationSpec-Driven Dev