Matias Sieff

    Mobile Engineer
    & Full Stack Developer

    12+ years building scalable Android and React Native apps. Specialized in mobile development, while expanding my expertise with modern web technologies and AI.

    Android
    React Native
    Kotlin
    Vue.js
    Node.js
    TypeScript
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    Professional Experience

    12+ years building scalable Android and React Native applications for startups and enterprises

    Software Engineer

    RedPADEL
    Jun 2025 - Present
    Remote (USA)

    Full-stack developer building responsive web applications using Vue.js, Next.js, and Node.js with MongoDB.

    Android Technical Lead

    The App Master (Hilti Group)
    Jan 2024 - Jun 2025
    Remote (Germany)

    Led technical evaluation and improvements for Hilti Group's Android app.

    Mobile Manager & Team Lead

    The App Master
    Feb 2023 - Jan 2024
    Remote

    Led Android and React Native development teams, driving adoption of best practices and mentoring developers to deliver scalable mobile products.

    React Native Engineer

    Lemon Cash
    Apr 2022 - Dec 2022
    Remote

    Developed security features including MFA, passcode reset with liveness proof, and multi-currency balance views using React Native.

    Lead Developer, Mobile SDKs

    GetintheLoop
    Sep 2021 - Mar 2022
    Remote (Canada)

    Designed and improved SDKs for Android, iOS and JS using Kotlin Multiplatform.

    Android Engineer

    GetintheLoop
    Jul 2019 - Aug 2021
    Remote (Canada)

    Contributed to Kotlin Multiplatform SDK for shared logic between Android and JavaScript apps.

    Freelance Mobile Developer

    Independent

    Nov 2015 - Present
    Remote (Worldwide)

    Delivered end-to-end mobile solutions for various clients including official artist apps, music players, chat apps, and productivity tools using Android native and React Native.

    Android Developer & Team Leader

    InfinixSoft
    Apr 2014 - Nov 2015
    Buenos Aires, Argentina

    Defined architecture and technology stack for client projects. Mentored junior developers and led training initiatives in Android development.

    Android Developer

    The App Master
    Apr 2013 - Mar 2014
    Buenos Aires, Argentina

    Early-career Android developer responsible for implementing features and learning core Android fundamentals.

    Technologies & Tools

    Full mobile and web development stack

    Mobile

    Android (Kotlin, Java, Jetpack Compose)
    React Native (TypeScript, JavaScript)
    Kotlin Multiplatform
    App Store / Play Console Deployment

    Frontend

    Vue.js
    React
    TypeScript
    JavaScript

    Backend

    Node.js
    GraphQL
    REST
    MongoDB
    Typegoose

    Architecture & Practices

    Clean Architecture
    Modularization
    Testing
    Code Reviews
    CI/CD (GitHub Actions, GitLab)
    Knowledge Sharing & Mentoring
    Scalable Design

    Tools & AI

    Firebase
    Expo
    AWS
    SonarQube (Code Quality)
    Process Automation
    AI-assisted Development
    Background Agents / Exploration

    Soft Skills & Strengths

    Team Leadership
    Problem Solving
    Product Thinking
    Adaptability & Continuous Learning
    Project Ownership
    Remote & Cross-cultural Collaboration