The GOATs
100 tracks · 7:48:09 · by Felipersas
DOOM
The first episode of DOOM (1993), in the shareware release id Software let people distribute, running in DOSBox inside the browser.
Arrows: move · Ctrl: fire · Space: open doors · Shift: run · Esc: menu
DOOM © id Software, unmodified shareware v1.9. Emulated by js-dos (GPL-2.0). The game and the emulator are a few MB and load only when you click.
About
I'm a software engineer focused on applied AI, with a full-stack base: backend, frontend, mobile and the infrastructure that runs it.
At FazzLeads, a company I co-founded for real estate agencies, I put into production an AI agent that answers and qualifies leads on WhatsApp and now books around 200 property visits a month. It runs on Mastra AI and MCP, behind guardrails, metrics and alerts. This portfolio has an agent of its own, grounded in the site's data and measured with evals. Before that, at MindGroup, I architected and shipped 3 production systems and took a critical query from 5s to 240ms. I'm at Keeper today, a fintech for graduation fundraising.
I'm studying Machine Learning (DeepLearning.AI certificate and a Systems Analysis degree at SENAI). Outside of work I build distributed systems and developer tools, including DemoCraft.
Experience
Projects(7)
Portfolio Agent
A durable, bilingual AI agent embedded in this portfolio to answer questions about my career, projects, and technical decisions.
Built with Vercel Eve and OpenAI's GPT-6 Luna, with generative UI rendered through json-render and a local multilingual Whisper pipeline running through Transformers.js in a Web Worker.
- Eve
- OpenAI
- json-render
- Transformers.js
- Next.js
DemoCraft
An open-source toolkit for creating polished and reproducible product demos from real application workflows.
Demo flows are defined in TypeScript, executed in a real browser with Playwright, and rendered deterministically with Remotion.
- TypeScript
- Playwright
- Remotion
- React
Real-Time Crash Game
A real-time multiplayer crash game where every cent a bet moves is posted to a double-entry ledger and every crash point can be verified by the player.
Games and Wallets, two NestJS services, settle bets through a choreographed Saga over RabbitMQ with a transactional outbox and an idempotent inbox. The ledger is SHA-256 chained per wallet and reconciled every 5 minutes.
- NestJS
- RabbitMQ
- PostgreSQL
- Redis
- WebSockets
PayFlow
A financial transfer system built with three Go microservices that communicate exclusively through asynchronous messaging.
Uses a choreographed Saga with no central coordinator, DDD boundaries, idempotent operations, and OpenTelemetry tracing to keep transfers consistent across distributed services.
- Go
- PostgreSQL
- RabbitMQ
- Docker
Fraud Detection
A neural network that flags fraudulent credit card transactions, built on 1.85 million simulated purchases and served by a FastAPI service as a versioned 6 KB model bundle.
Trained in Keras with a time-based split, PR-AUC as the metric and a cost-based decision threshold, then exported to ONNX and served with ONNX Runtime, so the API image needs neither TensorFlow nor scikit-learn. Each card's recent purchases live in Redis, shared by every replica.
- Python
- TensorFlow
- ONNX
- FastAPI
- Redis
- Docker
Mini-GPT
A decoder-only GPT written from scratch in PyTorch, one component at a time, each with its own tests, an experiment and a document that explains the math.
No nn.Transformer: a BPE tokenizer, causal multi-head attention, pre-norm Transformer blocks and a weight-tied LM head add up to 7,391,744 parameters, trained on CPU, CUDA or Apple's MPS over four Machado de Assis novels and a slice of the Portuguese Wikipedia.
- Python
- PyTorch
js-routines
Go-style concurrency for TypeScript: channels, select, synchronization primitives, cancellation and a deterministic scheduler for testing concurrent code.
Three modules: a scheduler that runs routines written as generators in an order set by a seed, for tests; async/await on the event loop, for production, with the same channels and primitives; and channels and a mutex on SharedArrayBuffer, for parallelism across workers.
- TypeScript
- Bun
- Node.js
Stack
Education
Associate Degree, Systems Analysis and Development
Technical Degree, Systems Development
Certifications(2)
DeepLearning.AI
Supervised Machine Learning: Regression and Classification