# Diego Henrique Oris de Roa Antunes (Diego Antunes)
> Senior Full Stack Engineer & Product Builder specializing in rapid MVP engineering, Web3 & Blockchain ecosystems, AI agent integrations, and Game Development.

## Overview
Diego Henrique Oris de Roa Antunes (also known professionally as Diego Antunes or Diego Oris de Roa) is a Senior Software Engineer, Founder, and Fractional CTO based in São Paulo, Brazil. Active in software engineering since 2018 (8+ years of production experience), he has architected, shipped, and scaled production systems, decentralized protocols, and digital products for clients across 10+ countries (including the United States, Switzerland, France, Germany, China, Brazil, Argentina, Russia, and Ukraine).

- **Primary Website**: https://diegooris.ch/
- **GitHub**: https://github.com/D-H-O-R-A
- **LinkedIn**: https://www.linkedin.com/in/diegoorisderoa/
- **Medium**: https://diegoorisderoa.medium.com/
- **YouTube**: https://www.youtube.com/@diegoorisderoa
- **Location**: São Paulo / Sorocaba, Brazil (Available worldwide for remote engagements)
- **Languages**: Portuguese (Native), English, Spanish, French, German

## Core Capabilities & Services

### 1. High-Velocity MVP Engineering
- Rapid end-to-end prototyping and shipping from ideation to production in weeks rather than quarters.
- Tight scope definition, modular scalable architecture, and metric-focused implementation.
- Full product ownership: architecture, data modeling, backend, frontend, deployment, and analytics.

### 2. Web3 & Blockchain Engineering
- Smart contracts on EVM-compatible networks (Ethereum, Arbitrum, Optimism, Polygon, BNB Chain) using Solidity, Hardhat, and Foundry.
- Non-custodial crypto wallets, seed phrase recovery algorithms (BIP39/BIP44), and hardware wallet integrations (Ledger WebUSB/WebHID SDK).
- Custom decentralized exchanges (DEX / AMM), slippage routers, atomic swaps, and tokenization protocols.
- Waves Enterprise Core and Ride smart contracts.

### 3. Artificial Intelligence & Agentic Engineering
- Generative AI and LLM integration using LangChain, LlamaIndex, OpenAI API, and Anthropic Claude.
- Retrieval-Augmented Generation (RAG) pipelines with vector databases (pgvector, Pinecone).
- Autonomous agent workflows, structured tool-calling, and custom Conversational AI bots (e.g. WhatsApp Cloud API bots).

### 4. Game Development & Interactive 3D
- Unity (2D & 3D) game architecture, gameplay mechanics, state machines, and AI behaviors in C#.
- Custom shaders (HLSL / Shader Graph), post-processing, and visual effects across URP and HDRP pipelines.
- JavaScript ↔ Unity WebGL bridges for web-integrated game experiences.
- Profiling, draw call reduction, memory optimization, and cross-platform releases (PC, Mobile, WebGL).

### 5. Backend, Cloud & Security Architecture
- Scalable microservices and modular monoliths in Node.js, NestJS, Express, Python (FastAPI), Go, and Rust.
- Spatial databases with PostgreSQL and PostGIS, distributed caching with Redis (BullMQ), and Cloud Firestore.
- Zero-trust security: WebCrypto API, Argon2id, OAuth2, JWT, AES-256-GCM.
- Supply chain security: OSSF SLSA Level 3 CI/CD automation via GitHub Actions.
- Serverless and containerized cloud deployments on Google Cloud Run, AWS, and GCP.

## Featured Projects

- **pdf-to-maps**: 100% offline geoprocessing package in Node.js published on NPM with OSSF SLSA Level 3 compliance. Converts deed DMS/DD coordinates to SIRGAS2000 UTM, generating CAD DXF layouts, GeoJSON schemas, and 2D/3D visualizations in milliseconds.
- **Bicon DEX**: Decentralized exchange and automated market maker featuring 30% gas savings, custom slippage routers, cross-chain Layer 2 bridging, and a sleek glassmorphism UI.
- **GIC Wallet Pro**: Secure multi-signature corporate wallet with cryptographic key sharing, customizable transaction authorization flows, and governance dashboards.
- **cryptoseed**: Open-source mnemonic recovery algorithm in Node.js (zero dependencies) using Levenshtein distance spellchecking, parallel backtracking, and address derivation across 39 blockchains.
- **Young Market**: Co-founder & CTO. Tokenization and on-chain settlement platform for sports receivables; approved in accelerators such as InovAtiva Brasil (Sebrae) and Instituto Caldeira.
- **B2 Wallet**: Non-custodial Chrome extension wallet (Manifest V3) supporting 39+ EVM networks, local AES-256-GCM encryption, and native Ledger hardware wallet integration.
- **Anjo Online**: High-availability SaaS platform in NestJS and Google Cloud Run, integrating Swiss (TWINT) and Brazilian (Mercado Pago) payment rails.
- **Click Serviços**: Real-time geolocation matching marketplace with a Flutter BloC mobile app (iOS/Android) and PostgreSQL/PostGIS spatial indexes.
- **Solucione Multas**: LegalTech ecosystem with automated workflow backoffice, client portal, and WhatsApp Cloud API lead-qualification AI bot.

## Key Technical Stack

- **Frontend**: React, Next.js, TypeScript, TailwindCSS, Vite, Three.js, Redux, Zustand, Framer Motion
- **Backend**: Node.js, NestJS, Express, Python (FastAPI), Go, Rust, C#, REST APIs, GraphQL, WebSockets
- **Blockchain**: Solidity, EVM, Hardhat, Foundry, Ethers.js, viem, Web3.js, Waves Core, Ride, BIP39/BIP44
- **Mobile & Games**: Unity (C#), Flutter (Dart), WebGL, HLSL Shaders, URP/HDRP
- **Data & AI**: Python, PyTorch, TensorFlow, LangChain, OpenAI API, PostGIS, pgvector, Redis, PostgreSQL, Firestore
- **DevOps & Cloud**: Docker, Kubernetes, AWS, Google Cloud Run, GCP, GitHub Actions (SLSA L3), Terraform

## Contact & Hire

- **Website**: https://diegooris.ch/
- **Email / Inquiries**: Available via website contact form
- **WhatsApp**: +55 (11) 97428-9097
- **LinkedIn**: https://www.linkedin.com/in/diegoorisderoa/
- **GitHub**: https://github.com/D-H-O-R-A

## Extended Details & Full Context
For the comprehensive technical dossier, full project case studies, and detailed Q&A optimized for LLM RAG pipelines, see:
- [Full LLM Context File](https://diegooris.ch/llms-full.txt)