Victor Augusto — Full Stack .NET/C# Developer

Hope Pet reconnects tutors who lost a pet with people who found an animal on the street, combining computer vision and geolocation to cross-reference photos and location data and increase the odds of a reunion.

A billing system for anyone who lives off recurring payments and doesn't want to become a full-time debt collector. Register a client, generate a Pix charge via Mercado Pago (QR code and copy-paste code), and track its status in real time with no manual polling: the dashboard updates itself the moment the payment lands. A background worker checks for overdue charges and sends a single reminder through the WhatsApp Business API, with an option to resend manually. The Mercado Pago webhook validates its signature and is idempotent, so a duplicate notification never creates a duplicate charge. Built with Blazor Server on .NET 10, a single project, with an in-memory queue via Channels and EF Core + SQLite. Demo scenario: a personal trainer billing a client, but the recurring billing logic works for any subscription-based business.

Built for cases where waiting for the whole audio file to finish isn't an option: captioning a meeting, following a call in progress, dictation. Audio is sent by upload (WAV, MP3, M4A, OGG, FLAC, AAC) or recorded directly in the browser via AudioWorklet, and transcribed in 3-4 second chunks that get replaced by a more accurate version every 15 to 20 seconds. Real-time communication runs on a SignalR Hub separate from the REST API, with automatic reconnection and resend by sequence number: if the connection drops, no audio chunk is lost. On the backend, real backpressure via Channel<T>: if transcription falls behind, writes block instead of blowing up memory. Frontend in React and TypeScript; transcription runs on Whisper large-v3-turbo, through the Groq API.

Every group has someone stuck holding the spreadsheet, trying to figure out who owes what to whom. RachaContas solves that inside Telegram, with nothing to install. Each participant joins the group and logs expenses as they pay for things (accepts amounts in other currencies, converted at the day's exchange rate), and when it's time to settle up, the bot simplifies the debts down to the smallest possible number of transfers between people, the same logic used by apps like Splitwise. Whoever needs to pay gets a real Pix QR code, generated locally from the registered key, with no external gateway involved. Runs as a Worker Service on .NET 10, with long-polling via the official Telegram SDK, SQLite and EF Core, and coverage from 67 automated tests.