Criciúma, BrazilWorking across borders

Hi, I’m Júlio Cesar Paes Filho.

Thoughtful
interfaces.
Solid foundations.

Software engineer with 12+ years of turning complex problems into clear, dependable digital experiences.

Frontend by focus. Full-stack by experience.

A toolkit shaped by real problems

  • ReactInteractive interfaces
  • TypeScriptType-safe applications
  • Node.jsAPI integrations
  • .NETEnterprise systems
People. Products. Real-world problems.

Good work starts with
understanding the problem.

Complex interfaces, changing integrations, and everyday business workflows. Here’s how I approach them.

Software EngineerInterfaces, services & observability

Making complex products feel simple.

Turning complex product requirements into maintainable interfaces and software systems, with experience in cloud services, observability, and microservices architecture.

  • React
  • TypeScript
  • React Query
  • AWS
  • Go (Golang)
  • Datadog
  • Microservices
My contribution

Using React Query to manage server data and TypeScript to make component contracts explicit, alongside experience with AWS, Go (Golang), Datadog, and microservices architecture. Partnering with designers to improve usability and accessibility, and turning product requirements into smaller features that can be delivered incrementally.

Reliable deliveryIntegration & regression prevention

Confidence when the pieces change.

Connecting frontend features to backend services and testing the boundaries where integrations can break.

  • Node.js & .NET
  • Jest
  • MSW
My contribution

Contributing to Node.js and .NET services and integrating APIs into React and Vue applications. Using Jest and MSW to exercise integration behavior and catch regressions as features and existing modules evolve.

Enterprise systemsOperational workflows & reliability

Built around the people who use it.

Turning operational requirements into useful enterprise features, diagnosing system issues, and helping teams use their tools effectively.

  • Progress 4GL
  • PowerBuilder & ExtJS
  • Systems analysis
My contribution

Working directly with operational stakeholders to understand their workflows, implement features, and resolve technical issues. Building and maintaining enterprise applications with Progress 4GL, PowerBuilder, .NET, and ExtJS, backed by on-site support and client training.

Craft meets structure.

Based in Criciúma, Santa Catarina.
Building with teams around the world.

An engineer’s mind.
A human perspective.

I like software that works well for the people on both sides of the screen.

My work sits at the intersection of thoughtful interfaces and reliable systems. I specialize in React and TypeScript, with a full-stack background that helps me see how all the pieces fit together.

I care about accessible experiences, maintainable code, and the conversations that turn a good idea into a useful product. Working closely with designers, product managers, and business teams is part of the craft.

Always building on the fundamentals

BSc, Information Systems

ESUCRI · 2014

Capstone on expert systems and data mining, awarded the maximum grade of 10/10.

The toolkit

The right tools.
Used thoughtfully.

Interfaces

  • React
  • TypeScript
  • Vue.js
  • React Query
  • CSS Modules
  • SASS

Under the hood

  • Node.js
  • .NET
  • API integration
  • Systems analysis

Built with care

  • Jest
  • MSW
  • Accessibility
  • UI/UX collaboration
  • Agile delivery

A decade of learning.
Still curious.

From enterprise systems to modern web products. The technologies have evolved; understanding the problem still comes first.

  1. to Present

    Software Engineer

    React · TypeScript · React Query · AWS · Go (Golang) · Datadog · Microservices · Jest · MSW

    Software engineering spanning accessible interfaces, AWS, Go (Golang), Datadog, microservices architecture, and integration testing.

  2. to Present

    Frontend & full-stack consulting

    React · Vue.js · TypeScript · Node.js · .NET

    API integrations, maintainable codebases, and delivery across different teams and architectures.

  3. to

    Business workflows & systems analysis

    Progress 4GL · Requirements analysis

    Enterprise features, operational process improvements, diagnostics, and user training.

  4. to

    Enterprise product development

    PowerBuilder · .NET · ExtJS

    Application architecture, new product development, and maintenance of existing systems.

  5. to

    System reliability & technical support

    Progress 4GL · Root-cause analysis

    Diagnosing enterprise software issues, delivering corrective solutions, and supporting users.

Have something
good in mind?

A product to build, a problem to untangle,
or just a conversation about good software.

jcpaesf@gmail.com