Raphael Serafim

Summary

Hi, I’m Raphael Serafim, a Full-Stack Web Developer with 8+ years of experience building robust, scalable, and user-focused web applications.

Experience

Senior Software Developer
Lysterium | Toronto, Canada | February 2025 - June 2025
On-site
Developed and maintained full-stack web applications using Node.js and React.js.
  • Designed and implemented custom software solutions, including APIs and web systems.
  • Main project: AI-based Technical Visit Scheduling System: Developed back-end APIs using Node.js, including integration with Twilio for automated calls.
  • Built an AI server using Ollama and a secondary API in Python to handle intelligent scheduling and device information collection.
  • The system allows an AI assistant to handle calls, ask questions about equipment, and automatically schedule technical visits.
  • Responsible for full back-end development, integration with AI services, and end-to-end API architecture.
Senior Software Developer
CJ Technologies | Toronto, Canada | April 2023 - October 2024
On-site
Developed and maintained full-stack web applications using PHP, Node.js, and React.js.
  • Main project: World of Blast, a decentralized gaming platform: Responsible for back-end development in Node.js and PHP, including integration with the Blast network (Ethereum L2 subnet).
  • Designed and deployed Solidity smart contracts, including battle logic, NFT collections, and an ERC-20 token for the platform’s economy.
  • Implemented front-end integration with MetaMask for seamless blockchain interactions.
  • At launch, the platform processed over $40,000 in transactions.
  • Collaborated with cross-functional teams to design and implement new features.
  • Optimized database queries to enhance performance and scalability.
  • Focused on cryptocurrency and decentralized gaming solutions, contributing to platform functionality and user experience.
Senior Software Developer | Personal Project
Freelance | March 2018 - Present
Remote
Creator and maintainer of an Unofficial WhatsApp API, started years ago before the official WhatsApp API was available.
  • Developed the back end using Node.js and TypeScript, managed with Docker containers for isolated instances, and MongoDB for database storage.
  • Built front-end dashboards with React.js and provided complete documentation via Swagger, making it easy for developers to integrate and understand.
  • Developed open-source SDKs for Node.js (npm) and PHP (GitHub), enabling hundreds of developers to implement WhatsApp-based projects and contribute to the project.
  • Currently running over 500 active instances, handling around 20,000 requests per hour, demonstrating scalability and reliability.
  • The project demonstrates strong initiative, full-stack development skills, and a commitment to creating accessible developer tools for the developer community.
Software Developer
CACHE SISTEMAS | Guarantã do Norte, Brazil | December 2017 - November 2022
On-site
On-site Responsible for designing and developing the entire college management system for UNIFAMA, including system architecture, back-end, and front-end.
  • Main project: Developed the full college management system, including student and class management, course creation, enrollment, and financial control.
  • Integration with banks for automatic invoice generation and online contract signing.
  • Automated the process in which students sign contracts digitally, automatically generating invoices for payment.
  • This innovation saved approximately BRL 100,000 per semester by eliminating manual printing and processing of payment slips.
  • Entrusted with full ownership of the project early in my career, I took the idea from concept to delivery, significantly improving operational efficiency.

Links

https://www.npmjs.com/package/@raphaelvserafim/client-api-whatsapp https://github.com/raphaelvserafim/api-sicredi-pix https://doc.api-wa.me/ https://github.com/raphaelvserafim/base-server-ts https://github.com/raphaelvserafim/base-react-typescript-vite https://github.com/raphaelvserafim/client-php-api-wa-me https://github.com/raphaelvserafim/chatbot-gpt-whatsapp https://www.npmjs.com/package/@raphaelvserafim/google-authenticator https://www.npmjs.com/package/@raphaelvserafim/google-drive-downloader https://worldofblast.com/

Languages

Portuguese Fluent
English Intermediate

Personal Information

Willing to relocate: Yes
Open work permit: valid for any employer in Canada.

Contact

📞 +1 437 522 3417
✉️ raphaelvserafim@gmail.com
📍 Toronto, Canada M5B 0C5
🌐 https://raphaelvserafim.com

Skills

PHP8 years
Node.js6 years
Python2 years
JavaScript - TypeScript8 years
Solidity2 years
HTML58 years
CSS - Bootstrap8 years
React / React.js4 years
Next.js4 years
React Native2 years
AJAX8 years
Laravel4 years
MySQL8 years
SQL8 years
MongoDB3 years
Firebase Database3 years
Blockchain6 years
Web36 years
MetaMask Integration6 years
DeFi2 years
Smart Contracts2 years
APIs - RESTful Web Services8 years
API Development / Integration8 years
Serverless APIs3 years
AWS - Amazon Web Services3 years
Full-Stack Development6 years
Software Architecture8 years
Architecture Design6 years
Database Design6 years
Testing4 years
Database Optimization6 years
System Integration6 years
Cryptocurrency Integration3 years
Object-Oriented Programming8 years
MVC6 years
Git / GitHub6 years
Docker3 years
Linux8 years
Security Best Practices6 years
Algorithm Development6 years
Data Structures Mastery6 years
Problem Solving8 years
Agile Methodologies6 years
Software Development Life Cycle6 years
SEO tools, Google Search Console6 years
Socket5 years
WordPress8 years
Machine Learning2 years
Ollama1 year

Education

Bachelor's Degree
Information Systems
UNIFAMA
Graduated in 2020

Certifications

Driving License
Social Worker License

Open Source Projects & Contributions

All projects are open-source and free, designed to help the developer community. They demonstrate my hands-on experience, versatility, and commitment to development beyond financial gain.

I am passionate about development and building tools that help other developers and companies accelerate their projects. I maintain multiple open-source projects, providing complete solutions, best practices, and documentation:

• Back-end Node.js: Base Server TS – ready-to-use template with database integration and authentication.

• Front-end React.js + TypeScript: Base React TypeScript Vite – follows architecture and documentation best practices.

• Security & Authentication: Google Authenticator TS – 2FA implementation.

• File Management: Google Drive Downloader – simplifies document downloads.

• AI & Bots: AI Mistral All, Omnitrade – APIs and bots for trading and AI operations.

• News & Notifications: News Portal, App News WPP – blogs and notification apps in React Native.

• WhatsApp Integration: Chatbot GPT WhatsApp – seamless chatbot integration.

• Financial Tools: Sicoob Boleto Generator – generate payment slips with Sicoob bank.