Sergio M.

I build mobile and web products end to end: Flutter apps backed by Laravel or Node.js APIs, deployed on AWS. More than 10 of them are live in production right now, from cashless payment platforms to health-insurance self-service apps. I'm the co-founder of Pollux, a software development cooperative based in Rosario, Argentina. Behind me there's a senior team (mobile, backend, DevOps, UI), so I can scale from solo work to a full squad without you managing anyone but me. What I do best: - Cross-platform mobile apps in Flutter (iOS + Android + web): payments (Stripe, Mercado Pago), QR flows, biometrics, push notifications. - Solid backends: Laravel and Node.js REST APIs, MySQL/PostgreSQL, queues and third-party integrations (Firebase, HubSpot, WhatsApp). - Front-ends in Vue.js/Nuxt and React; admin dashboards and back offices. - DevOps and reliability: AWS, Docker, CI/CD with GitHub Actions, observability with Grafana, Sentry and OpenTelemetry. Recent work (see my portfolio): a cashless payments platform for events, port-machinery inspection apps, medical appointment systems, insurance CRMs and e-commerce portals. I'm also a university professor: I explain technical decisions in plain language and document everything. You can work with me in English, German or Spanish.