I'm Jônatas Gomes

LojaPix is a full-stack product for small businesses that sell via Pix. Sellers set up a branded storefront with products and photos, share a public link (or custom subdomain), and customers pick items on their phone. The app totals the cart and generates a Pix QR code for the exact amount — payments go straight to the seller’s Pix key.

Built with FastAPI and server-rendered Jinja2 templates, SQLAlchemy + Alembic, and Turso/libSQL in production on Vercel. Media lives on Cloudflare R2 behind a CDN; coverage includes pytest and Cypress, with GitHub Actions CI.

ContaCerta is a privacy-focused Flutter app that automatically detects bills, boletos, and Pix payments in the user’s Gmail inbox and organizes them into a unified “accounts payable” list.

The mobile client authenticates exclusively via Google Sign-In and never reads Gmail directly. A Python FastAPI backend—deployed as serverless functions on Vercel—handles OAuth token exchange, incremental Gmail sync, sender whitelisting, and charge detection from email text, HTML, PDF attachments, and QR codes. Refresh tokens are encrypted at rest; local storage keeps only structured charge data, not full emails.

The architecture separates concerns cleanly: Flutter (Riverpod, go_router, Dio, Hive) on the client, and a layered API (routers → services → repositories → SQLAlchemy/Turso) on the server, with automated tests covering parsing and business logic.

DivideAI is a full-stack web app that makes splitting restaurant and bar bills fair and effortless. Friends open a shared session, invite others via QR code or link, add items from a live menu or manually, assign who consumed what, and settle the bill with service fees and couvert included — no spreadsheets, no awkward math.

The product is built as a monorepo: a Next.js frontend (React 19, TypeScript, Tailwind, PWA), a FastAPI backend with JWT and Google auth, and an async scraping stack (Celery, Redis, Playwright) that discovers venues and keeps menus up to date in a shared Turso/libSQL database. Real-time updates (Pusher) and web push keep everyone in sync while the bill is being built.

It showcases end-to-end product thinking: collaborative UX, typed API contracts from OpenAPI, anonymous and authenticated identity, and a production-minded data pipeline behind the scenes.

Rastro is an Android fintech app that builds daily financial awareness by capturing spending automatically from bank push notifications—no manual entry required.

When a Brazilian bank app notifies a purchase, Rastro’s notification listener parses the amount and merchant with regex patterns for major banks (Nubank, Inter, Bradesco, Itaú, C6, PicPay, and more), stores the transaction offline in SQLite, and syncs it to a FastAPI backend through an idempotent offline-first queue. The API authenticates users with JWT, persists data on Turso (libSQL), categorizes expenses, and can generate contextual insights with Anthropic’s Claude API.

The Flutter client presents a Portuguese (pt_BR) dashboard with spending progress, category breakdowns, and savings potential, while biometric unlock and local notifications support privacy and daily summaries. The architecture is designed for reliability on mobile networks: capture first, sync when online.