Hi, I'm
Marcos.
> Backend Developer
I design and build what runs behind the scenes: robust APIs, clean architecture, well-modeled data and integrations that don't fall over when the real world shows up.
Who's behind the server
I'm a backend developer focused on building the part nobody sees but everybody feels: REST and GraphQL APIs, well-isolated business rules and databases that tell the truth. I work with Node.js, NestJS and PostgreSQL, applying Clean Architecture and DDD so the code stays changeable years after deploy.
I enjoy the hard backend problems — idempotency, concurrency, money as decimals, webhooks as the source of truth — and Python automations that give hours back to the team. I'm always learning and shipping what I learn to production.
Professional experience
Support & Customer Success Analyst
cVortex
At cVortex, an AI-powered omnichannel SaaS platform, I work at the intersection of customer, product and engineering: combining technical support, customer success and building internal tools that drive efficiency and save time.
- AI integrations in the omnichannel SaaS platform, powering automation and support
- Troubleshooting and problem-solving across complex workflows
- Consuming and integrating APIs (REST and GraphQL) and writing SQL queries
- Python automations that saved ~20h per week during the rollout phase
- Building internal applications that integrate systems and boost efficiency
- Improved a RAG generator that builds RAG knowledge bases on Gemini, raising the quality of AI-assisted answers
- Strong grasp of business rules with direct contact with product and customers
Featured projects
Backends I've built, focused on architecture, data consistency and best practices.
Raízes do Nordeste — Backend API
Management API for a multi-unit restaurant chain (franchises): omnichannel orders (app, web, kiosk, counter, pickup), payments and a loyalty program — built with Clean Architecture and DDD per bounded context.
- Clean Architecture + DDD per bounded context, with a pure domain (zero framework imports)
- Payments with webhook as source of truth: idempotent, transactional and UNIQUE(order_id) against double payment
- Decimal-safe money pipeline: Postgres Decimal → big.js → JSON string, float never appears
- Channel-aware orders with server-side price validation (anti-tampering) and optimistic locking on status transitions
- Repository Pattern with Symbol injection (swappable ORM) and a global exception filter mapping domain errors → HTTP
nexio-frontend — Web App
Web interface for the Raízes do Nordeste app (future nexio-core): consumes the omnichannel orders, payments and loyalty exposed by the API, focused on responsive UX and real-time integration.
Technologies I use
My day-to-day toolbox — from the endpoint to the database, through the infrastructure.
Backend
Databases
Architecture & Quality
DevOps & Tools
Frontend
Let's talk
Got a project in mind or want to talk backend? My inbox is always open.