Júlio César Oliveira Rios

Salvador, Brazil · julio@byjuliocesa.com · linkedin.com/in/byjuliocesa/ · github.com/Julio0Cesar · byjuliocesa.dev

Full-stack software engineer who starts from the business problem. Proposed and led the rewrite of four legacy systems into a single ERP, and built in one week a kiosk app now running in 100+ retail stores. I lean towards the backend, and I'm drawn to game engines, embedded and distributed systems, and Rust.

Experience

VX CaseSalvador, Brazil

Full-Stack Software EngineerOct 2025 – Present

Brazilian premium tech-accessories retailer: own-label audio, bags and lifestyle products, plus device warranty and repair, across 100+ mall stores and kiosks and online.

  • Proposed the architecture for replacing four legacy systems (outdated Angular, NestJS microservices, C# ASP.NET, Laravel/Zend) with one Next.js + Elysia/Bun monorepo, defended it to the tech lead, and led the implementation.
  • Cut the time to deliver a new screen from 2–3 weeks to under one day, and a heavy request from 12 s to 1.3 s after database migrations.
  • Built a kiosk app alone in one week after meeting the CEO and marketing; plain HTML/CSS/JS with a JSON content file let non-developers update it without code. Now runs in 100+ points of sale across Brazil.
  • Co-built the company's in-house project-management tool (Next.js + Go, magic-link auth) that replaced ClickUp for the whole company.
  • Built most of the ERP hardware module, a Vue checkout and the Getnet payment integration.
  • Helped design a per-project Git flow with preview environments for reviewers and PO-approved releases, reducing production/development drift.
  • Took part in the infrastructure migration from AWS to DigitalOcean, Kubernetes and ArgoCD.

TecnotrendsRemote

Software Development InternApr 2024 – Sep 2025

  • Maintained and extended a legacy C#/ASP.NET system with a React frontend and MySQL.

SENAI CIMATECSalvador, Brazil

IT Intern (support, DBA, networks)Jul 2022 – May 2024

Brazilian technology and research institute.

  • Automated support and database tasks in Python; administered MySQL and Linux servers; monitored infrastructure with Zabbix.

Bahia State Department of Agriculture (SEAGRI)Salvador, Brazil

IT Support InternOct 2021 – Jun 2022

  • Supported computers and network infrastructure, including server racks and switches.

Projects

  • LyricsLens — Open-source Linux app (Rust + GTK4) that overlays synced lyrics on any window. lyricslens.byjuliocesa.dev
  • Orbit — Personal finance app with a Go backend, built end to end from design to deploy. orbit.byjuliocesa.dev
  • how-i-build — Technical case-study site (Next.js/MDX). how-i-build.byjuliocesa.dev

Education

UNIFACSSalvador, Brazil

B.Sc. Computer ScienceExpected Dec 2026

Federal University of Bahia (UFBA)Salvador, Brazil

B.Sc. Computer ScienceExpected Dec 2029

SENAI CIMATECSalvador, Brazil

Technical Degree, Systems Analysis and Development2022 – 2024

Federal University of Bahia (UFBA)Salvador, Brazil

Certificate, Functional Programming with Lisp2023

Skills

Languages: TypeScript, Go, Rust (learning), SQL, C

Front-end: Next.js, React, Vue, Angular, Tailwind CSS

Back-end: Elysia/Bun, NestJS, OpenAPI

Data: PostgreSQL, MySQL, MongoDB, Redis, S3

Infra: Docker, Kubernetes, ArgoCD, DigitalOcean, AWS, Bitbucket Pipelines, GitHub Actions, Vercel

Desktop & mobile: Tauri, Expo/React Native, GTK4

Languages (spoken): Portuguese (native), English (upper-intermediate: fluent reading and listening)