Yago Fernandes.
System_Profile

Yago Fernandes
Yago Fernandes.

Full Stack & Platform Engineer. Builder of physical and digital things.

Executive_Summary
"Build production systems as a sole technical owner, with a focus on integrations, reliability, and clean architecture. I treat code as a narrative — not just instructions, but a way to explain the system so others can reason about it, debug it, and understand the intent behind it."
Deployment_History
2025 – PRESENT

Lead Engineer

Greenbudz — Remote

Own backend, infrastructure, and production reliability for an e-commerce platform. Work with product and design on technical direction as sole technical owner.

  • Built a 76-component design system and payment flows with production-ready integrations.
  • Own banking, ERP, and logistics integrations in production.
  • Cut build time from 48 minutes to 8. Ship to production on a 48-hour cadence.
  • Built self-hosted internal infrastructure, saving $650+/month.
  • Led a server migration that improved observability and reliability.
2023 – 2024

Software Developer

Medical Preceptorship Selection Program — Salvador, Brazil

Independent contract. Built an applicant management system for a postgraduate selection program from scratch.

  • Automated applicant and document intake into PostgreSQL.
  • Designed an approval workflow for hospital review boards.
  • Migrated from NestJS to Bun/Elysia to simplify deployment.
2023 – 2024

Independent Technical Work

Open Source
  • Dokploy container-based deployment automation.
  • Built Uyuni — a "Git for financial decisions" engine for projections and scenario comparison. Deterministic, auditable, extensible plugin system, terminal UI. Active development.
2020 – 2023

Full-Stack Software Engineer

Toki Network — Remote

Architected financial, behavioral, and clinical systems. Led a 5-person team during the CTO's medical leave.

  • Designed systems with DDD and Event Sourcing. Built an internal Event Sourcing library used across multiple systems.
  • Implemented Stripe off-session payment flows and lifecycle monitoring.
  • Led a full JavaScript-to-TypeScript migration. Refactored an outsourced system, resolving 800+ issues.
  • Mentored junior engineers who later joined full time.
Technical_Stack

Languages

TypeScriptJavaScriptGo

Backend

Node.jsNestJSExpressBunElysia

Frontend

ReactNext.jsTailwindMedusaJS

Databases

PostgreSQLMongoDBRabbitMQ

DevOps

DockerGitHub ActionsDokployLinux

Architecture

DDDCQRSEvent SourcingSOLID

Expertise

Platform EngineeringCI/CDERP & Logistics IntegrationsMonorepo Architecture

Interests

3D PrintingCNCLaser CuttingRepRapFOSS
Education
Expected 2028

BSc Software Engineering (in progress)

Estácio (EAD)
Incomplete

BSc Computer Science

UFOP
Incomplete

BSc Economics

UFOP
Languages
EnglishBrazilian PortugueseSpanish

Want to work together?

Especially interested in projects involving platform engineering, integrations, or anything that sits at the edge of hardware and software.

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