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Kelvin Miranda

@kelvinmiranda

Senior full-stack software engineer building sustainable TypeScript/React/NestJS and Ruby on Rails products with strong testing and observability.

Brazil

Message

What I'm looking for

I’m looking to build sustainable products with TypeScript/React/NestJS and Rails, pairing clean architecture with TDD/BDD, strong testing, and observability. I want teams that value UX, performance, accessibility, and pragmatic, maintainable code.

I’m a senior full-stack software engineer focused on shipping pragmatic, maintainable applications with TypeScript/React/NestJs and Ruby on Rails. I build full-stack projects “from scratch to evolving production codebases,” emphasizing end-to-end CRUDs, UX/performance, and consistent testing with TDD/BDD and reliable componentization.

In 2025, as a remote freelancer in Brazil, I worked across Ruby, Rails, Hotwire (Turbo + Stimulus), TypeScript, Next.js/React, tRPC, Prisma, and PostgreSQL—delivering features with accessibility, i18n, theming (light/dark), and SSR/SSG tuning. I also model ERDs from scratch, handle integrity/migrations, document APIs through Swagger and ADRs, and reduce debugging effort with end-to-end observability using OpenTelemetry—pairing it with queues/workers for heavy tasks and better resilience.

Previously, I delivered user-facing improvements and reliability gains at AB InBev (Ambev), including a rewards system and an e-commerce platform with accessibility upgrades, regionalization, age-gate functionality, and LGPD flow optimization. Earlier roles reinforced my fundamentals: improving SQL performance, optimizing React rendering/network behavior, caching with Redis, refactoring legacy modules, and implementing automated tests—while also contributing to open source SOS-RS (flood response logistics) with a TypeScript/NestJs/React/Prisma/PostgreSQL stack.

Experience

Work history, roles, and key accomplishments

Current

Software Engineer

Current

Freelance

Jan 2025 - Present (1 year 5 months)

Built and evolved full-stack web applications with Ruby on Rails and TypeScript/React/Next.js, delivering end-to-end CRUD features. Improved reliability through consistent testing (TDD/BDD), enhanced UX with accessibility/i18n and theming, and reduced debugging effort using OpenTelemetry.

Ruby Ruby on Rails TypeScript Next.js React NestJS PostgreSQL Hotwire OpenTelemetry Jest

Software Developer (OSS)

SOS-RS

May 2024 - Jun 2024 (1 month)

Contributed to a web application that helps coordinate distribution of supplies and volunteers during floods in Rio Grande do Sul. Implemented shelter filtering, ZIP-code lookup, form validation and authenticated field behavior using a TypeScript/NestJS/React stack.

TypeScript NestJS React Prisma PostgreSQL React Query Vite Jest Docker

Software Engineer

AB InBev

Dec 2020 - Dec 2023 (3 years)

Developed and maintained customer-facing features for a rewards system, including event subcategories, highlights, and lucky numbers. Optimized performance, improved accessibility and UX, and supported a premium beer e-commerce experience with regionalization, age-gating, LGPD flow, and GraphQL/Vtex integrations.

React TypeScript SWR GraphQL React Testing Library Accessibility Performance Optimization Storybook

Full Stack Developer

Eureka Labs

Feb 2021 - Oct 2021 (8 months)

Fixed critical issues and shipped new features for large-scale logistics systems, improving SQL query performance and response consistency. Refactored frontend components to reduce rendering/network overhead and implemented automated tests to increase deployment reliability.

TypeScript React NestJS TypeORM PostgreSQL MySQL Redis Jest API Testing

Full Stack Developer

Devninjas

Jul 2020 - Jan 2021 (6 months)

Contributed to high-traffic systems focused on performance and maintainability, including integrations with VTEX and other commerce platforms for order synchronization. Refactored legacy modules to improve readability and testability, fixing bugs and strengthening system stability using clean code practices.

React Redux Redux Saga NestJS Ruby on Rails Go gRPC Testing

Full Stack Developer

Appmoove

Feb 2019 - Jun 2020 (1 year 4 months)

Maintained and enhanced features for a rotating parking system, including frontend redesign, bug fixes, and new functionalities. Built reporting and delivery MVP capabilities by optimizing SQL/background jobs, adding unit/integration tests, and reducing database bottlenecks.

React Redux MySQL Sequelize Ant Design Jest Docker

Web Designer

Oxy Creative

Jan 2016 - Aug 2017 (1 year 7 months)

Developed institutional and e-commerce websites using WordPress as a CMS. Built custom functionality via WordPress plugins and theme functions in PHP and adapted design assets into production-ready frontend with HTML/CSS/JavaScript.

WordPress PHP HTML CSS JavaScript Frontend E commerce Support Asset Optimization

Education

Degrees, certifications, and relevant coursework

Universidade Tecnológica Federal do Paraná (UTFPR)

Computer Science, Computer Science

2012 -

Studied Computer Science topics including mathematical logic, algorithms and data structures, database fundamentals, software engineering, and operating systems.