Things I've shipped.
A selection of products, libraries, and open-source work. Some in production, some still teaching me lessons.
Products
iTOP: Inscrições TOP
Multi-tenant SaaS in production for managing large Legendários events: registrations, payments (PIX/card with webhook reconciliation), QR Code check-in, contract generation with biometric digital signature, boarding plan, and real-time dashboards. Processes real money, real events, and hundreds of participants in production. Predecessor of inscricoestop.com.br before the pivot.
Unicrow
Web3 escrow platform on Ethereum. Contributed to the SDK, blockchain indexer, and smart-contract integrations. Production-grade TypeScript SDK that turned a multi-week onboarding into a same-day setup.
Pi: AI Agent Toolkit
An open-source toolkit for building AI coding agents, plus a working assistant (pi) built on top of it. One clean API across OpenAI, Anthropic, and Google, a streaming agent runtime with tools and state, a terminal experience, and reusable chat UI for both terminal and web. TypeScript monorepo.
Dale Carnegie AI Trainer
An AI coach in the style of Dale Carnegie. Describe a situation and it returns a diagnosis, which of the 53 principles to apply, and an action plan. It also has a role-play mode, an application diary, and a searchable principles library. Built with the Vercel AI SDK.
Canetaço: e-signature SaaS
A Brazilian e-signature SaaS with legally valid document signing and native WhatsApp delivery from day one. Built on Next.js 16, Supabase, Drizzle, and Inngest, with the WhatsApp Cloud API, AWS SES email, Stripe billing, and a timestamping flow grounded in Brazilian law (MP 2.200-2, Lei 14.063). In active development.
3D Print Management System
Internal management system for an on-demand 3D printing studio. Client registry, filament stock control per location with low-stock alerts, a drag-and-drop production queue with status tracking, payment status, and a full audit log. Real-time sync across devices via Supabase, with a mobile-first interface built for the shop floor.
Agenda Editor: custom planner covers
An end-to-end flow to design and order custom planner covers. Customers pick a template, personalize it with their logo, name, fonts, and colors in a Fabric.js editor, configure the planner interior, preview it as a 3D flipbook, and check out with Pix via Asaas. Includes order tracking and an admin area. In active development.
tgmarinhopro.com (this site)
The very site you are reading. A bilingual personal platform and technical blog built as a living AI interface: MDX content through Velite, next-intl routing, RSS and llms.txt generated at build, and a daily journal pipeline. Designed and shipped in an agentic, AI-native workflow.
Legendários MS
Website for a nonprofit community movement, built as volunteer work. It centralizes event info, registration links, photo galleries, and prep guides, improving communication between participants and leaders. Next.js, Tailwind, and Vercel.
Tools & experiments
Fluent5: English 5x5x5
An English learning web app built on a 5x5x5 massive-repetition method: read, listen, write, and speak the same short story or phrase five times per session, three times a day, for five days. Pairs leveled stories with browser text-to-speech, Supabase accounts, and progress tracking, in a light and dark PWA.
English Study
A web app to study English with paired texts, translations, and audio. Content lives as markdown and mp3 collections, and a build script generates the catalog the React frontend reads. Mobile-friendly navigation with a content drawer and a fixed bottom bar.
Fixed Income Calculator
A calculator to compare Brazilian fixed-income investments side by side. Enter an amount and a period, and it shows the net return for each option (Tesouro Direto, CDB, LCI/LCA, Fundo DI, Poupança) after taxes, with a detailed breakdown.
Investor Calculator
A school-style financial calculator inspired by the CVM Investor Calculator. Basic arithmetic, financial functions (PMT, present and future value, IRR, NPV), Price and SAC loan simulations, a household budget, and advanced percentage math.
DynamicForms React
A browser-based drag-and-drop form builder, like a small Google Forms. Add and configure fields across nine types, reorder, duplicate, and delete them, then preview a working form with validation. Built with React, Vite, and shadcn/ui.
Open source
README-ecoleta
Three README templates I created for the Rocketseat blog, paired with the Ecoleta project (a marketplace connecting people to waste collection points). One of my most shared open-source repos, used as a starting point by hundreds of developers.
GoBarber API
Backend API for a barbershop scheduling app, the capstone of Rocketseat's GoStack 11 bootcamp. Built around SOLID principles and DDD-style layering, with JWT auth, appointments, providers, dependency injection (tsyringe), and tests.
Members
A CRUD app to manage members and people, with a dashboard, backed by a GraphQL API on Hasura. Built with Next.js, Apollo, and Chakra UI.
Meetapp
Full-stack meetup organizer (Backend + Web + Mobile). Final challenge from the Rocketseat Bootcamp. React, React Native, Node, Redux.
BMI Calculator (React Native)
A Body Mass Index calculator for Android, built in React Native and published on Google Play. A small multi-screen app with custom styling, internationalization (pt-BR and en), and a clean UI inspired by a Dribbble design.
Be the Hero
Full-stack app connecting NGOs with donors, built during Rocketseat OmniStack week. It helps small organizations raise funds for their causes.