Cristian González, Developer in Oshawa, ON, Canada
Cristian is available for hire
Hire Cristian

Cristian González

Verified Expert  in Engineering

Mobile Application Developer

Oshawa, ON, Canada

Toptal member since March 7, 2025

Bio

With 10+ years in the software industry and expertise in Android, Cristian modernizes legacy systems and builds scalable, maintainable apps that boost user satisfaction. His innovations have cut RMA tickets by 40%, improved load times, and reduced crash/ANR rates by 10%, delivering tangible results for his clients. Cristian also leads projects integrating secure protocols and cutting‑edge technologies, consistently exceeding expectations.

Portfolio

IOHK
Android SDK, Kotlin/Native, Coroutines, Jetpack Room, REST, Ktor...
Presto
Android SDK, Leadership, Android Jetpack, Android Studio, Java, Kotlin/Native...
Mapsted
Android SDK, REST, Android Jetpack, Model View ViewModel (MVVM), JSON, Android...

Experience

  • Android - 10 years
  • Digital Innovation - 10 years
  • User-centered Development (UCD) - 10 years
  • Android Jetpack - 7 years
  • Complex Problem Solving - 6 years
  • Kotlin/Native - 4 years
  • Leadership - 2 years
  • Jetpack Compose - 1 year

Availability

Full-time

Preferred Environment

Android, Android SDK, Android Jetpack, Jetpack Compose, Kotlin/Native, Kotlin Multiplatform, XML, JSON, Dependency Injection, Kotlin

The most amazing...

...thing I've done is lead the development of a device health monitoring solution, collecting data from over 500,000 devices nationwide.

Work Experience

Senior Android Engineer

2022 - 2024
IOHK
  • Developed the Identus Edge Agent SDK from early stages using Kotlin Multiplatform, decentralized identifiers (DIDs), DID communication (DIDComm), anonymous credentials (AnonCreds), and SD-JWT.
  • Integrated SSI protocols to ensure strong encryption and secure data exchange, laying the groundwork for seamless future implementations.
  • Leveraged interface-oriented architecture, coroutines, and SQLDelight to improve code reliability and maintainability.
Technologies: Android SDK, Kotlin/Native, Coroutines, Jetpack Room, REST, Ktor, JSON Web Tokens (JWT), Android, Android Studio, Android Jetpack, Kotlin Multiplatform, XML, JSON, JavaScript, Complex Problem Solving, Digital Innovation, User-centered Development (UCD), Unit Testing, Clean Architecture, Kotlin, Software Development, Mobile Development, Mobile Apps, Mobile App Development, Android Development, Android App Development, Software Engineering, Kotlin Multiplatform Mobile (KMM), Decentralized Identifiers (DIDs), SQLDelight

Senior Android Engineer

2020 - 2022
Presto
  • Engaged as a project lead and orchestrated the design and development of an Android device's health monitoring system using Jetpack components, RxJava, and Retrofit, monitoring 500,000+ devices across the US and Canada.
  • Enhanced system reliability by identifying performance bottlenecks, improving stability, and contributing to a more responsive user experience.
  • Refactored the Android app legacy code by migrating from Java to Kotlin and adopting MVVM architecture and Jetpack components like Room, ViewModel, and LiveData to streamline data handling and scalability.
Technologies: Android SDK, Leadership, Android Jetpack, Android Studio, Java, Kotlin/Native, Model View ViewModel (MVVM), Android, XML, JSON, Dependency Injection, Coroutines, Jetpack Room, Complex Problem Solving, Digital Innovation, User-centered Development (UCD), Unit Testing, Clean Architecture, Kotlin, Software Development, Software Engineering, Mobile Apps, Mobile App Development, Mobile Development, Android Development, Android App Development, RxJava, Retrofit, Room, LiveData

Android Engineer

2019 - 2019
Mapsted
  • Engineered a mall-oriented indoor GPS Android application from concept to MVP using MVVM and Jetpack components like ViewModel, LiveData, Room, and Navigation.
  • Delivered the initial product on schedule, enabling iterative improvements.
  • Collaborated with the iOS team to ensure common features and designs were maintained.
Technologies: Android SDK, REST, Android Jetpack, Model View ViewModel (MVVM), JSON, Android, Android Studio, XML, Java, Jetpack Room, Complex Problem Solving, Digital Innovation, User-centered Development (UCD), Software Development, Software Engineering, Mobile Apps, Mobile App Development, Mobile Development, Android App Development, Android Development, Minimum Viable Product (MVP), LiveData, Room, Navigation

Mobile Developer

2016 - 2019
FeaturePoints
  • Architected and deployed Android and iOS apps, integrating REST APIs and delivering dynamic views and smooth user interactions.
  • Learned Swift rapidly to build a feature-rich iOS app alongside the Android version, successfully launching both within six months.
  • Employed MVVM and Jetpack components to enhance maintainability, reduce technical debt, and boost user satisfaction.
Technologies: Android SDK, Swift, iOS, Java, Android Studio, Xcode, REST, Android, Android Jetpack, XML, JSON, Jetpack Room, Model View ViewModel (MVVM), Digital Innovation, User-centered Development (UCD), Software Development, Software Engineering, Mobile Apps, Mobile App Development, Mobile Development, Android App Development, Android Development, iOS App Development, REST APIs

Android Developer

2014 - 2016
Jungle Prize
  • Developed an app to list weekly game challenges with a chance to win a prize. This required communication with Unity games and a REST API.
  • Created a bridge for the Android app to communicate with the on-device Unity games to set difficulty and other variables and fetch results for the scoreboard.
  • Built a strong foundation based on the requirements, used top-performing libraries for different tasks, and worked with the iOS team to ensure both platforms performed similarly.
Technologies: Android, Android SDK, Java, REST, JSON, XML, Digital Innovation, User-centered Development (UCD), Software Development, Software Engineering, Mobile Apps, Mobile App Development, Mobile Development, Android Development, Android App Development, REST APIs

Experience

Indoor Navigation App for Malls

https://mapsted.com/indoor-navigation/
An Android app that brings indoor navigation to mall customers. The app uses proprietary technology that enables users to navigate without hardware or GPS location.

The app provides mall and store information, an interactive 3D map of the mall, and a way to define single or multiple routes within the mall.

Data Analytics App

An Android app that analyzes Canadian immigration data to help immigrants applying for permanent residency better understand the process and their chances of getting into the system.

The app displayed real-time data of the express entry draws of invitations and notified users when that happened.

Digital Identity Android SDK

https://github.com/hyperledger-identus/identus/
An Android SDK that provides features for digital identity.

The SDK combined DID and DIDComm 2 technologies for encrypted and secure communication. It also uses cryptography libraries to encrypt public and private keys and verifiable credentials, such as AnonCreds, SD-JWT, and zero-knowledge proofs.

Education

2009 - 2011

Associate's Degree in Software Development

Monlau Formación Profesional - Barcelona, Spain

Skills

Libraries/APIs

Jetpack Room, RxJava, Retrofit, LiveData, REST APIs

Tools

Android Studio, Android Jetpack, Xcode

Languages

Java, Kotlin, XML, JavaScript, HTML, C++, Swift, Python

Frameworks

Android SDK, Ktor, JSON Web Tokens (JWT)

Platforms

Android, iOS, Firebase

Storage

JSON

Paradigms

Dependency Injection, REST, Model View ViewModel (MVVM), Unit Testing, Clean Architecture, Mobile Development

Other

Kotlin/Native, Jetpack Compose, Coroutines, Complex Problem Solving, Digital Innovation, User-centered Development (UCD), Kotlin Multiplatform, Leadership, Software Development, Mobile Apps, Mobile App Development, Android Development, Android App Development, Software Engineering, Kotlin Multiplatform Mobile (KMM), Decentralized Identifiers (DIDs), SQLDelight, Room, Minimum Viable Product (MVP), Navigation, iOS App Development, Zero-knowledge Proofs

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring