Senior Frontend / Full-Stack Engineer — I take complex systems (LLMs, real-time, heavy third-party integration) and ship them as products people actually use.
TypeScript · React · Next.js · Node.js · Ruby on Rails
🇰🇷 Korean-Brazilian, based in São Paulo 🇧🇷 · 15+ years building software, 9 of them remote for US teams · EN / PT / ES / KR
Hivy · Senior Frontend Engineer · Techstars '25
Led the product, frontend and mobile layers of the redesign as the only engineer on the client side: rebuilt a consumer prediction-markets app, a social layer over Kalshi and Polymarket, from Figma into production Next.js 15 / React 19 / TypeScript, page by page, without breaking the live product. Built the client layer over our wallet and transaction services: a provider-aware wallet UI that adapts labels, validation and signing to the active backend, plus funding, withdrawal and cross-provider transfer flows. Shipped to web and to Android through the Solana dApp Store.
Chat Nexus · Senior Frontend Developer · Los Angeles
AI fan-engagement platform. Built the AI persona system — creators configure personality, tone and conversation context so every reply stays in character at scale — plus real-time 1:1 text and voice messaging with optimistic UI for sub-second perceived latency, live in-app calling, and a multi-tenant creator dashboard with subscriptions and payments.
Streetwyze · Senior Frontend Engineer · 9 years, remote for the US
Community mapping platform recognized by the Obama White House Opportunity Project, partnered with Google, YouTube, Uber and Fitbit. Worked with the team to separate three differentiated products out of one Ember + Rails 7 / PostGIS / Elasticsearch application, split by feature flags, scope and product boundaries rather than by splitting the codebase, and built two of the three. Owned engineering estimates and delivery planning end to end.
branchyard · Rust
Paired git worktrees CLI. One command creates isolated dev environments across every repo in a stack — deterministic port allocation, Docker isolation, per-repo setup — and one command tears the whole thing down when the feature ships. Cross-platform CI, three install channels (Homebrew tap, cargo install, curl), shell completions for zsh/bash/fish.
| Layer | Tools |
|---|---|
| Frontend | TypeScript · React · Next.js · Tailwind · Framer Motion · real-time UI (WebSockets / SSE) |
| Backend | Node.js · Ruby on Rails · PostgreSQL / PostGIS · Elasticsearch · Redis · REST · GraphQL · JSON:API |
| AI / LLM | OpenAI · Claude · Gemini · RAG · MCP servers · agent tooling |
| Systems & tooling | Rust · Python · Docker · GitHub Actions · Puppeteer |
Also Ember.js — nine years of production maintenance on a large-scale app, today on Ember 7.2, Embroider 4 and Vite 7, with .gjs strict-mode components, ember-data 5.8 and pnpm 10 on Corepack. I co-led the 5.11 to 7.2 migration with our platform lead, through the 5.12 LTS, 6.0 and 6.12 gates. Real experience, just not the headline.
📬 pablogravielseo@gmail.com · LinkedIn
Open to Senior Frontend / Full-Stack roles — remote, US/EU timezones.