Android & Full-Stack Developer
I craft efficient, secure and scalable apps, from Jetpack Compose to full-stack web. Based in Mallorca, Spain.
📍 Mallorca, Spain
My name is Fernando González Serrano, but everyone calls me Fer or Feryael Justice. I started programming at 15, exploring web development and desktop software, and never stopped building since.
Most recently I worked as an Android Developer at ExisTI, a tech consultancy, on a banking app, building it from scratch and migrating a legacy version, alongside a great team in a large company like NTTData.
Along the way I've shipped desktop enterprise software with Delphi at Tec-Soft, and full-stack web products with Laravel, Vue.js, Node.js and TailwindCSS. My passion is creating efficient, secure and scalable applications, and growing on impactful projects.
4+
Years coding
6+
Shipped apps
5+
Core stacks
From native Android apps to full-stack platforms, real products, real users.
A bilingual, browser-based tool for creating Google Play and App Store screenshots. Compose original screenshots with device frames, captions and templates, then export store-ready RGB PNGs in a ZIP. Optional FLUX.2 Klein AI generates decorative backgrounds locally in the browser. No accounts, backend or paid inference APIs.
A secure, end-to-end encrypted messaging and vault app available on all platforms. Spring Boot + JPA backend, STOMP for real-time messaging, a Next.js web client with TanStack Query, Web Crypto API for client-side encryption, native Android with Jetpack Compose and native iOS with SwiftUI.
Full-stack e-commerce for a billiards store on Node.js: React (Next.js) + Express, MySQL, VPS on Debian. Secured with JWT and bcrypt, custom admin panel, Stripe checkout, an AI chatbot and ML-powered product suggestions.
The mobile companion for Vince Pro Shop, built with Kotlin Multiplatform + Compose Multiplatform for both iOS and Android. Clean architecture with Koin, SQLDelight, Ktor, Room, Datastore, CredentialManager/Keychain, Material 3 and Stripe.
My programming YouTube channel, showcasing mobile projects and knowledge across different Android topics.
~2 years of professional experience
Dec 2024 – Jun 2025 · 6 months
Tech consultant focused on Android. Collaborated on a banking app with NTTData, building 5+ new features with Kotlin, Jetpack Compose, Hilt, MVVM and Retrofit, and shipping secure builds with Proguard/Dexguard.
Sep 2023 – Aug 2024 · ~1 year
Maintained and developed internal web products with Laravel and Vue.js, in an Agile team using Bitbucket for version control. Started as a higher vocational training internship (Sep–Dec 2023).
May 2022 – Aug 2022 · 4 months
Developed enterprise software in Delphi Seattle for desktop environments, including tooling such as PDFBuilder.
Tools and technologies I use daily across mobile, web and backend.
Open to new opportunities and collaborations. The fastest way to reach me is by email.
nano9gs@hotmail.es
