Guilherme de M. C. Costa

Fullstack Developer · TypeScript · Java · React · Spring Boot

echina725@gmail.com +55 11 949940557 Atibaia, SP - Brazil LinkedIn GitHub

About Me

I'm a Fullstack Developer with a strong focus on TypeScript and Java, working across React, Spring Boot, and the Cloudflare ecosystem. Currently building AI-powered SaaS products at Mr. Turing, where I've contributed to architectural decisions — from decoupling frameworks and designing modular cache systems to implementing workflow engines and multi-LLM integrations.

Beyond my day-to-day work, I enjoy building tools that solve real problems for developers. My open source projects include code-telescope, a keyboard-first fuzzy finder for VS Code, and Tracker.nvim, a productivity analytics plugin for Neovim — both with active community traction on GitHub.

I care deeply about code quality, observability, and building software that scales. Whether it's designing clean abstractions, writing meaningful tests, or exploring new technologies, I'm always looking for ways to improve both the product and the craft.

My Work Experience

Here are some of my professional experiences and the projects I have worked on.

Software Developer - Mr. Turing

Apr 2025 - Present | Remote

  • Full-stack development on an AI SaaS product using Cloudflare Workers, Hono, Supabase, and React.
  • Refactored the application's logging system, introducing standardization, observability, and end-to-end traceability.
  • Redesigned the storage module (R2) with an extensible architecture supporting multiple providers.
  • Built a decoupled, modular cache system based on Cloudflare KV, designed for future extensions.
  • Implemented an internal workflow engine for orchestrating processes and complex automations.
  • Decoupled the Hono framework via adapters, increasing testability and architectural flexibility.
  • Built multi-LLM applications integrating different language model providers via AI Gateway.
  • Created a centralized policy system for consistent authorization across the entire application.
  • Strengthened a culture of unit and integration testing, continuously improving code quality.

Fullstack Developer Intern - Elevaty

Jan 2023 - Mar 2025 | Remote

  • Maintained and evolved features for a customer card management system using React and Node.js.
  • Built workflow configuration software from scratch for a multi-channel notification system (email, SMS, WhatsApp) using Spring Boot, React, PostgreSQL, and AWS SQS.
  • Provided support to the Customer Success team, developing product and user experience awareness.
  • Led the initiative to adopt a culture of automated testing within the engineering team.

Technical Administrative Assistant - Constanta Industrial Ltda.

Sep 2022 - Dec 2023 | Jarinu, SP

  • Built real-time dashboards to monitor 260,000 IoT devices, improving service quality by 40%.
  • Developed graphical interfaces using Python integrated with REST APIs for data analysis and reporting.
  • Automated tasks with Python, including email automation, Office 365 integration (Excel, Word), and web automation with Selenium.
  • Managed ETL pipelines using MySQL and PostgreSQL and performed data analysis with Pandas, NumPy, and Plotly.
  • Identified strategic LoRa network gateway installation sites to enhance signal quality.

Education

Certifications

Courses

Skills

🧑‍💻 Programming Languages

TypeScript, Java, Python (Pandas, NumPy), C++, Lua, SQL

⚙️ Frameworks & Technologies

React, Spring Boot, NestJS, Hono, Fastify, Vite, Tailwind CSS, Shadcn/ui, TanStack Query, TanStack Table, Selenium, Plotly, Streamlit

📊 Databases

PostgreSQL, Supabase, Oracle, MySQL, Redis

☁️ Cloud & Infrastructure

AWS (SQS, S3, Lambda), Cloudflare (Workers, R2, KV, Durable Objects, Queues, Hyperdrive, AI Gateway)

🤖 AI & LLM

Multi-LLM integration, Cloudflare AI Gateway, prompt engineering, AI-powered application development

🔍 Version Control & Practices

Git, Clean Architecture, Design Patterns, TDD, Code Review, CI/CD, Agile/Scrum

🤝 Soft Skills

Critical Thinking, Adaptability, Proactivity, Creativity, Communication

🌐 Languages

Intermediate English, Native Portuguese

Projects

code-telescope

A Telescope.nvim-inspired fuzzy finder extension for VS Code, bringing keyboard-first navigation to your entire workflow. Search files, symbols, commands, and more without leaving the keyboard.

Technologies: TypeScript, VS Code Extension API

Go to repo

Tracker.nvim

A Neovim plugin that tracks and generates statistical data on user operations within the text editor. Logs various activities and provides insights into user habits, workflow efficiency, and editor usage patterns through real-time dashboards.

Technologies: Lua, Neovim

Go to repo

Github Analytics

A platform to visualize and analyze metrics from GitHub repositories. Provides insights into contributions, collaborator activity, and code evolution with interactive charts and detailed reports.

Technologies: Fastify, React, TailwindCSS, Shadcn/ui, TanStack Query, TanStack Table

Go to repo

SLA - Real Time Monitoring Application

Web application that monitors service quality and IoT devices via interactive 3D dashboards. Simulates network improvements and provides predictive analysis.

Technologies: Python (Streamlit, Pandas, Plotly), MySQL

Go to repo

SteamLens

A project designed to analyze and track real-time and historical data from Steam games, offering insights into player trends and game performance.

Technologies: Spring Boot, Redis, PostgreSQL, Next.js

Go to repo

Semantic React Components

A library of reusable, semantic React components and useful hooks designed to enhance web applications. Focuses on well-structured, easy-to-integrate components that promote best practices in React development.

Technologies: React, TypeScript

Go to repo

Temporal - 2D Game

A 2D game built with C++ and SDL2, implementing an Entity-Component-System (ECS) architecture for flexible and scalable management of game entities. Features collision detection and a dynamic event system.

Technologies: C++, SDL2

Go to repo

Dotfiles

A complete set of personal dotfiles including custom configurations for my workspace: window manager, Neovim, and general Linux personalizations.

Technologies: Lua, Linux, Shell

Go to repo