Frontend Engineer
Pulse Bar
High-fidelity animated site for an AI app/game generator, with hand-built motion, popup transitions computed from getBoundingClientRect and interactive cursor demos.
Next.js · React · Tailwind · CSS keyframes
Hi, I'm Rafa.I build thingsfor the web.
About
Senior Frontend Engineer with 7+ years shipping production React and Next.js applications in TypeScript.
My work lives where engineering meets design: design systems, real-time data-dense interfaces, and the performance details that make a product feel fast.
Frontend-first with full-stack range: I own the TypeScript/Node.js backend behind my features. I also bring LLMs into product UX where they earn their place.
Selected work
Featured builds, from AI pipelines to on-chain finance.
Projects I'm proud to have shipped.
Creator, Frontend and Full-Stack Engineer
Graph Wars
Turn-based artillery where every shot is the graph of an f(x) you type, and LLMs play too: pick OpenRouter models and watch them duel by writing functions. A pure functional game engine shared by the browser and a socket.io server for online rooms.
Next.js · TypeScript · Canvas · mathjs · Zustand · socket.io · OpenRouter
GameFi · TelegramFrontend and Full-Stack Engineer
Ladder Labs · Sugar Quest
A real-time multiplayer game UI holding thousands of concurrent sessions at a steady 8Hz tick, smooth on low-end devices. Reached 23,000+ active users and won the Sonic Mobius Hackathon. Backed by a full TypeScript stack I architected end to end.
Next.js · WebSockets · AWS Cognito · Solana Actions · Go · Capacitor
Frontend Engineer
Mallow Art
A mobile-first storefront for a curated NFT art marketplace on Solana: limited editions, live artwork drops and burn mechanics. Delivered with an embedded engineering team through Cold Brew Digital.
React · Solana · IPFS
Senior Full-Stack Engineer
Collector Crypt · Incursion
An order management and fulfillment interface bridging digital and physical goods, with a unified Solana + Ethereum checkout in a single React flow. Under the hood, the print-to-ship lifecycle runs on deterministic state machines.
Next.js · Drizzle · Neon · Solana · viem · Cloudflare R2
Senior TypeScript & AI Engineer
Forecast · Cold Cast
A Chrome extension turning unstructured web data into typed, scored business intelligence, replacing a fully manual prospecting workflow. Deterministic extraction plus an LLM review-and-correct pass, all client-side.
TypeScript · Chrome MV3 (WXT) · React · Zustand · DeepSeek · Zod
AI Agent · WhatsAppSenior Full-Stack Engineer
PadelFlow
An AI agent living inside a padel club's WhatsApp that answers questions, sends booking links and coaches players. No app, no integration, no training; a web dashboard tracks bookings, FAQs and voice notes.
TypeScript · Turborepo · WhatsApp Cloud API · LLM agents
Web3 · AffiliateFull-Stack Engineer
Ladder Labs · Buddy.Link
A fully on-chain affiliate network on Solana: unified creator profile, shareable Blinks and instant payout per conversion.
Next.js · TypeScript · Solana · Blinks
Senior Full-Stack Engineer
Autoestima-se
Institutional site for a national NGO democratizing mental-health care for women and young people in social vulnerability: donation funnel, transparency pages and a trilingual (PT/EN/ES) experience.
Next.js · TypeScript · Sanity CMS · next-intl · Cloudflare Workers
Healthtech · SaaSSenior Full-Stack Engineer
Bem-Te-Vi
An integrated operating system for a multidisciplinary health clinic, replacing three disconnected tools. End-to-end NFSe issuance with a self-healing invoice queue (per-line backoff, distributed locks) resilient to a degraded government API.
Next.js · Prisma · Supabase · NextAuth · TanStack Query · Zod
AI · Local-firstSenior Full-Stack Engineer
Radar
Finds and qualifies leads across Twitter/X, LinkedIn and Google. MV3 extensions passively intercept traffic; Express services own the data behind a single SQLite owner; a Next.js dashboard runs the human-in-the-loop. A 12-signal heuristic ranks before LLM triage.
TypeScript · Express · SQLite · Next.js · MCP · Zod
NFT-Fi · AnalyticsFrontend and Full-Stack Engineer
Wolf Capital
A high-performance analytics dashboard surfacing LTV ratios, volume and liquidation alerts in real time. Behind it, an ecosystem of interconnected Node services processing 10k+ monthly transactions.
Next.js · React Query · Redis · Recharts · Solana Web3.js
GameFi · Web3Full-Stack Engineer
Degen Legends
NFT gaming platform pairing an in-app breeding constructor with a merch marketplace. Automated, event-driven reward distribution and a social-verification pipeline removed manual moderation from the reward flow.
NestJS · React · PostgreSQL · Prisma · Docker
Full-Stack Engineer
Align
Solana-native DAO governance with multisig treasuries, NFT/token-weighted voting and on-chain hackathons; NestJS + GraphQL backend on the Helium SDKs, Sign-In-With-Solana frontend.
NestJS · GraphQL · TypeORM · Anchor · Solana · Helius
Full-Stack Engineer
Pump Science
Decentralized-science platform for funding and tokenizing research, built embedded into the client's team during a Solana hackathon.
Next.js · React · Solana Web3.js · Anchor · Supabase
Full-Stack Engineer
Azevedo Store
Counter-Strike 2 skins store with float/wear filters, persistent cart, authentication and a complete admin panel.
Next.js · Prisma · Postgres · NextAuth · React Query · Zod
DeFi · Real-timeBackend Engineer
Blue Giant
Real-time asset & price streaming engine with sub-second latency, scaling to thousands of concurrent connections over Server-Sent Events. Cut API latency ~60% via Redis read-through caching and targeted query optimization.
NestJS · PostgreSQL · Prisma · Redis · SSE · Helius
More engagements
TreeShake
Web3 · DAO
Front-end and a scalable Node API for NFT DAO management on Solana, with wallet-adapter social login and a Discord bot for community ops.
Next.js · Node · MongoDB · Solana · Discord.js
Solana Ecosystem
NFT · Consulting
14+ NFT collections for entrepreneurs and artists via Metaplex Candy Machine v2: whitelisting, secure wallet integration and Arweave/IPFS storage.
Metaplex · Solana Web3.js · Arweave · IPFS
Open source & personal
agente-pessoal
AI · Automation
Terminal-only personal assistant on Claude Code driving Gmail, Calendar, Drive and an Obsidian vault, with defense-in-depth prompt-injection hooks that gate sensitive tools after any external read.
TypeScript · Claude Code · MCP · Google APIs · Playwright
chip-22kado
Go · Discord bot
~20 MB single-binary Go music bot that delegates audio decoding and voice streaming to a Lavalink JVM over REST/WS; DAVE/E2EE compliant, self-hosted on a homelab with its own CI runner.
Go · discordgo · Lavalink · Docker
homelab
Infra as code
Ansible IaC for a two-machine homelab; a self-hosted GitHub Actions runner applies the playbook over SSH with ephemeral secrets and zero inbound exposure.
Ansible · Docker · GitHub Actions · Ollama
Client sites · Cold Brew Digital
Fast, SEO-ready institutional sites, landing pages and lead funnels, with polished motion and performance built in from the first line of code.
Speech therapist in Jaraguá do Sul, with a playful, parent-friendly brand funneling visitors straight to WhatsApp.
Stack
Tools I reach for daily.
01Languages
TypeScriptJavaScriptGoPython
02Frontend
ReactNext.jsTailwindshadcn/ui
03Backend
Node.jsNestJSExpressHonoGraphQLRESTMicroservices
04Data
PostgreSQLDrizzlePrismaNeonRedisBullMQSQLite
05Real-time & Arch
WebSocketsSSEEvent-DrivenState MachinesZodOpenAPI
06Cloud & Infra
Vercel EdgeCloudflare R2AWSGCPDockerKubernetesCI/CDSentryChrome MV3 (WXT)Playwright
07Web3 interfaces
Solana Web3.jsAnchorMetaplexHelius
08AI in product UX
AnthropicOpenAIDeepSeekGeminiOllamaVercel AI SDKMCPStructured OutputsStateful Agents
Contact
Let's build
something good.
Currently open to new projects: full-time, direct contract, consulting or through Cold Brew Digital. Always happy to chat.