End‑to‑end web and mobile apps. I build React Native (Expo) apps for iOS/Android, Next.js websites, and Node/Express APIs with PostgreSQL/Prisma and Supabase.

Yes. I integrate ESP32 devices over MQTT (HiveMQ/Mosquitto), secure token workflows (HMAC/JWT), and real‑time control for use cases like door access and smart lighting.

React, React Native (Expo), TypeScript, Next.js, Node.js/Express, PostgreSQL/Prisma, Supabase, Docker, MQTT, and CI/CD (Vercel, EAS, Fastlane/TestFlight).

I follow OWASP and GDPR best practices, enforce HTTPS/TLS, use rate‑limiting and Helmet, apply scoped tokens, and review auth flows (JWT refresh, short‑lived session tokens).

Kickoff → scoped roadmap → iterations in weekly sprints. You get GitHub access, regular demos, and a staging environment. I ship to TestFlight/Play Internal and Vercel.

Yes. Unit and integration tests, basic E2E where needed, profiling for app start time and bundle size, Lighthouse targets on web, and crash/error monitoring.

Fixed‑scope or hourly, depending on uncertainty and speed needed. We start with a short discovery call and a written proposal with milestones.

Lisbon time (UTC+1, Europe/Lisbon). Remote‑first. I work with clients in Portugal and abroad and adapt to overlapping hours.

Yes. Optional monthly maintenance that covers monitoring, security updates, minor improvements, and store submissions when needed.

Send me a message with your goals and constraints. I will respond with next steps and propose a lean MVP path.