Jeff Johnson, Android Developer in Denver, CO, United States
Jeff Johnson

Android Developer in Denver, CO, United States

Member since October 28, 2020
Jeff has five years of varied Android experience. It is both his specialty and passion. He has worked with Fortune 100 companies to implement and refine their mobile app vision to greenfield R&D work with a startup on mobile SDKs to support computer vision. Jeff will bring your Android app to life. Equally comfortable making architectural improvements and fixing bugs as plotting out and building something new, Jeff would love to help you with all things Android.
Jeff is now available for hire

Portfolio

Experience

Location

Denver, CO, United States

Availability

Part-time

Preferred Environment

Firebase, Cloud Firestore, Android

The most amazing...

...project I've worked on is a mobile SDK, created from scratch, to support a machine learning, computer vision offering.

Employment

  • Senior Android Developer

    2017 - PRESENT
    GoSpotCheck
    • Maintained 99+% crash-free user rate for an Android application with > 10,000 monthly active users, while adding countless new features.
    • Built a greenfield Android application using the Firebase suite of tools to support an image recognition offering.
    • Built scalable Android libraries to support image recognition integration into other applications.
    • Rearchitected an important user profile persistence layer of the application, which previously caused crash-free user rates to dip to 93%. After rearchitecting, the crash-free user rate returned to 99%.
    Technologies: Cloud Firestore, Firebase, SQLite, Android
  • Android Engineer

    2015 - 2016
    Solstice Mobile
    • Reduced the average duration of an important, multi-threaded, chained network call in a client’s app by 75% by retooling the handling of individual network calls.
    • Integrated external libraries and RESTful APIs into Android apps.
    • Improved screen lag by 95% on the map screen of a client’s app by implementing a bi-directional HashMap to circumvent slow internal look-up functions.
    Technologies: OkHttp, SQLite, Android

Experience

  • Computer Vision Support SDK

    An Android SDK that allows users to capture photos and receive immediate feedback on the quality of those photos using frameworks such as MLKit, OpenCV, and TensorFlow Lite, and then submit those photos to a back end. The SDK can also receive results from that same back end and display the annotated photos and other useful aggregate data to the user and provide useful feedback on what they submitted.

    The SDK works entirely offline, data syncs in real-time, and is easily integrated into any Android app.

Skills

  • Languages

    Kotlin, Java
  • Libraries/APIs

    Retrofit
  • Platforms

    Android, Firebase
  • Other

    OkHttp, Data Structures, Algorithms, Coroutines
  • Paradigms

    Model View Viewmodel (MVVM)
  • Storage

    Cloud Firestore, SQLite

Education

  • Bachelor's degree in Physics, Computer Science, Mathematics
    2011 - 2015
    Occidental College - Los Angeles, CA

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