# Nelson Toledo — Senior Software Engineer

> Nelson Toledo is a Senior Software Engineer with over 14 years of professional experience specializing in backend engineering, distributed architectures, legacy modernization (Uniface, Oracle PL/SQL to modern Node.js, Go, React, C# .NET), messaging/queues, and practical AI workflow integration.

## Profile Summary
- Name: Nelson Toledo (Nelson Matheus Toledo)
- Title: Senior Software Engineer
- Email: nelsonmatheuss@gmail.com
- Location: Maringá, Paraná, Brazil (Available for Global Remote Work)
- LinkedIn: https://www.linkedin.com/in/nelson-toledo-39a805192/
- GitHub: https://github.com/ntdev-xyz
- Website: https://ntdev.xyz

## Core Expertise & Technologies
- Legacy & ERP Modernization: Uniface (14+ years specialist), Oracle PL/SQL, ERP modules (Financial, Tax, Logistics, Electronic Invoicing)
- Backend & Distributed Systems: Node.js, Go (Golang), C# / .NET, PHP, RESTful APIs, Microservices, Clean Architecture
- Frontend: React.js, Next.js, TypeScript, JavaScript (ES6+), Tailwind CSS
- Messaging, Queues & Workers: RabbitMQ, Redis Queues & Pub/Sub, Asynchronous Processing Pipelines
- Databases & Storage: PostgreSQL, Oracle Database, MySQL, Redis, SQLite
- AI & Automation: LLM Integration (OpenAI, Anthropic Claude), Multi-agent Workflows, Prompt Engineering, Structured JSON Outputs
- DevOps & Tools: Docker, Git, CI/CD, Linux

## Key Projects
- Assis by Coolhub: WhatsApp multi-agent automation platform with asynchronous Redis/RabbitMQ workers and LLM integration.
- Nottea: Offline-first Markdown knowledge base and note-taking application for developers.
- Adpilot by Coolhub: AI-powered digital advertisement creation and campaign management SaaS.
- QR Shield: Security-first QR Code reader for Android featuring real-time heuristic risk analysis (antiphishing, Pix verification, Wi-Fi inspection) with 100% on-device privacy (https://ntdev.xyz/qrshield).
- DFE API & Dashboard: High-performance Electronic Tax Document (NF-e, NFS-e, CT-e) engine and dashboard.

## Career History
- Vertti (2019 – Present): Senior Software Engineer — Enterprise systems integrating Uniface with Node.js, Go, React, Redis, RabbitMQ, Docker, C# .NET, and LLM automation.
- Rovitex (2019): ERP Systems Analyst — Financial, Tax, and Commercial order integration using C# / .NET, Uniface, PL/SQL.
- Romagnole (2011 – 2019): Software Developer — 8 years maintaining and modernizing enterprise manufacturing ERP with Uniface, PL/SQL, RabbitMQ, Java.

## Languages & Certifications
- English: C2 Proficient (EF SET 73/100)
- Portuguese: Native
- Education: B.S. in Systems Analysis & Development (UniCesumar)