Andrei is available for hire
Hire AndreiAndrei Istrate
Verified Expert in Engineering
Software Developer
Cluj-Napoca, Cluj County, Romania
Toptal member since March 15, 2022
Bio
Andrei is a senior mobile developer with over six years of experience building and maintaining robust mobile applications. He specializes in Android development and has a vast knowledge of the tools currently used for Android application development, including Java and Kotlin. Also, he has experience in working with cross-platform frameworks like Flutter.
Portfolio
Tinybeans
Android, Kotlin, Java, Android Jetpack, Sentry, GitHub Actions, Codecov...
Globant
Java, Kotlin, Flutter, Android NDK, Android, Charles, New Relic, Jira...
Fortech SRL
Java, Kotlin, Android, Android NDK, Jenkins, Continuous Integration (CI), SSL...
Experience
- Android - 7 years
- Agile - 6 years
- Databases - 6 years
- Java - 6 years
- Object-oriented Programming (OOP) - 6 years
- Firebase - 4 years
- Kotlin - 4 years
- Jira - 4 years
Availability
Full-time
Preferred Environment
MacOS, Windows, Mobile Development
The most amazing...
...project I've led as a lead Android developer provided aid for users with disabilities. The app is used in the train stations of London.
Work Experience
Android Developer
2023 - 2024
Tinybeans
- Modified entire subscription based model within the mobile application that increased the app's monthly revenue by more than 30%.
- Rewrote the entire Android application, changing entire legacy code with up-to-date standard architecture that considerably improved the product's UX and increased the app's rate on the Google Play Store by almost two points.
- Upgraded Cl/CD pipelines to include code coverage verification that increases code quality and minimizes faulty app behavior.
- Integrated 3rd-party ad providers that brought in a 4% increase in app revenue.
- Implemented an entire home feed feature that increased user engagement and app retention by 40%.
- Integrated multiple analytics providers that allowed us to measure user interaction and made future A/8/C feature testing possible.
Technologies: Android, Kotlin, Java, Android Jetpack, Sentry, GitHub Actions, Codecov, Google Ads, Leanplum, Grafana, Firebase, Mobile Applications, Jetpack Compose, Data Modeling, Apache Maven, Scalability, Large-scale Projects, CI/CD Pipelines, GraphQL, Amazon Web Services (AWS), Android Development, Application Lifecycle Management (ALM)
Senior Mobile Developer
2021 - 2022
Globant
- Worked in a team specializing in support, performance, and observability by facilitating and providing software-based solutions for a leading digital product in the entertainment industry.
- Enhanced the UI/UX and provided multiple video streaming performance upgrades.
- Integrated third-party video streaming analytics software with multiple stream services custom components.
- Resolved multiple Google Ads-related issues and reduced the application crash rate by providing custom analytics solutions.
- Held multiple technical team introduction discussions related to cross-platform mobile technologies (Flutter).
Technologies: Java, Kotlin, Flutter, Android NDK, Android, Charles, New Relic, Jira, Confluence, Breadboarding, Firebase, ExoPlayer, RxJava 2, Dart, Test-driven Development (TDD), Integration Testing, Mobile Development, Android Studio, Unit Testing, Agile, Mobile App Development, Telecommunications, REST APIs, APIs, RxJava, Model View ViewModel (MVVM), Video Streaming, Mobile, Cross-platform, Android SDK, Gradle, Mobile Apps, Google Play Store, Coroutines, Android Jetpack, Continuous Integration (CI), Authentication, Push Notifications, User Experience (UX), User Interface (UI), Android Animations, Subscriptions, Debugging, Mobile Applications, Jetpack Compose, Kotlin Multiplatform, Kotlin Multiplatform Mobile (KMM), Data Modeling, Apache Maven, Scalability, Large-scale Projects, GitHub Actions, CI/CD Pipelines, Android Development, Application Lifecycle Management (ALM)
Senior Mobile Developer
2020 - 2021
Fortech SRL
- Led an Android mobile team on a leading digital product within the housing industry.
- Provided multiple software-based solutions to improve the product's overall performance and decrease battery usage through multiple refactoring cycles. Battery consumption had an overall reduction of 35% while doing main flow app operations.
- Implemented custom QR code scanner solutions and integrated them with multiple US delivery services.
- Acted as a lead technical recruiter and conducted multiple technical interviews for Android-related positions.
- Provided custom SSL (Secure Socket Layer) solutions for a mobile application in the military industry.
- Developed a custom, offline, continuous integration process using Jenkins for a network restrictive product in the military industry.
Technologies: Java, Kotlin, Android, Android NDK, Jenkins, Continuous Integration (CI), SSL, SSL Certificates, Jira, RxJava, Agile, Mobile Development, Android Studio, Unit Testing, Mobile App Development, Telecommunications, Figma, REST APIs, Minimum Viable Product (MVP), Education, Flutter, Cloud Firestore, APIs, Model View ViewModel (MVVM), WebSockets, Video Streaming, MySQL, Mobile, Android SDK, Gradle, Mobile Apps, Firebase, Google Play Store, QR Codes, Coroutines, Android Jetpack, Integration Testing, Test-driven Development (TDD), RxJava 2, ExoPlayer, Breadboarding, Confluence, Authentication, Push Notifications, User Experience (UX), User Interface (UI), Android Animations, Subscriptions, Debugging, Mobile Applications, Bluetooth Low Energy (LE), Dagger 2, Kotlin Multiplatform, Kotlin Multiplatform Mobile (KMM), Data Modeling, Apache Maven, Scalability, Large-scale Projects, CI/CD Pipelines, Android Development, WebView, Application Lifecycle Management (ALM)
Mid Mobile Developer
2018 - 2020
Wolfpack Digital SRL
- Acted as a team lead/developer and built two mobile applications that were a part of a digital product within the transportation industry meant to assist users with disabilities, notifying staff to support them with train onboarding.
- Worked with real-time, client-server communication through WebSockets and Firebase Realtime Database. Created a custom chat feature that allowed users to share live locations via Mapbox.
- Developed an app that provides an improved alternative for taking meeting notes. The app records meeting conversations and returns full transcripts of the entire conversation through IBM Watson AI.
- Successfully migrated multiple Java-based Android projects to Kotlin and refactored entire app architectures from MVP to MVVM.
- Improved an app's UI/UX and performance; also upgraded audio file data transfers by converting the audio files from an mp3 format to Ogg using FFmpeg.
Technologies: Java, Kotlin, Android, Android NDK, Continuous Integration (CI), Jira, Mobile Development, Android Studio, Unit Testing, Agile, Mobile App Development, SMS, Telecommunications, Figma, REST APIs, Minimum Viable Product (MVP), Education, Cloud Firestore, APIs, RxJava, Model View ViewModel (MVVM), WebSockets, MySQL, Mobile, Android SDK, Gradle, Mobile Apps, Spreadsheets, Microsoft Excel, Firebase, Google Play Store, QR Codes, Android Jetpack, Integration Testing, RxJava 2, Confluence, Authentication, Push Notifications, User Experience (UX), User Interface (UI), Android Animations, Subscriptions, Debugging, Mobile Applications, Dagger, Dagger 2, Data Modeling, Apache Maven, Android Development, WebView, Application Lifecycle Management (ALM)
Mid Mobile Developer
2017 - 2018
Nordlogic Software
- Provided software solutions for an app designed as a controller for a third-party camera. Applied multiple video editing techniques through FFmpeg libraries.
- Built an application that displays all social events based on the user's location and preferences through communication with Facebook API. The app architecture was an MVP.
- Created a presentation application for a popular Hollywood makeup artist. Provided custom views implementation to resemble iOS native UI components. Integrated the app with Spotify API, as well as third-party payment with Two Tap.
Technologies: Java, Android, Android NDK, Embedded Java, Mobile Development, Android Studio, Unit Testing, Agile, Mobile App Development, SMS, REST APIs, Minimum Viable Product (MVP), APIs, Model View ViewModel (MVVM), Bluetooth, MySQL, Mobile, Smart Devices, Android SDK, Mobile Apps, Microsoft Excel, Google Play Store, Authentication, User Experience (UX), User Interface (UI), Android Animations, Debugging, Mobile Applications, Bluetooth Low Energy (LE), Dagger, Dagger 2, Data Modeling, Apache Maven, Android Development, WebView, Application Lifecycle Management (ALM)
Junior Mobile Developer
2016 - 2017
ServUsTECH
- Developed a mobile business management application using REST APIs, Android SDK components, and custom views.
- Provided software solutions to improve UI/UX and increase application performance by minimizing memory leaks and battery usage on multiple applications.
- Developed a social media mobile application using Geolocation, Maps API, and REST API. Refactored app architecture and improved UI/UX.
Technologies: Java, Android, Mobile Development, Android Studio, Mobile App Development, REST APIs, APIs, Bluetooth, Mobile, Android SDK, Mobile Apps, Microsoft Excel, Google Play Store, User Experience (UX), User Interface (UI), Debugging, Mobile Applications, Dagger, Java Native Interface (JNI), Apache Maven, Android Development, WebView, Application Lifecycle Management (ALM)
Experience
Capturi
Capturi is a Java-based Android app that increases meeting performance by providing an improved alternative to taking notes. The app would record a meeting conversation and through IBM's Watson AI was returning a full transcript with the entire conversation. I worked on improving application performance, fixing bugs, and handling result transcription real-time updates.
Cinefapp
An Android-based app for movie-related information. The app gives the ability to save all the movies a user wants to see and have a list of their favorite ones. Users can also stay up to date with upcoming movies and have a top list of the best ones.
This was a personal project, and I handled all levels of development, implementation, and design.
This was a personal project, and I handled all levels of development, implementation, and design.
Sama | Spyfall
A cross-platform game application developed in Flutter. The app is a great way to keep things interesting at parties and friends and family gatherings.
This was a personal project, and I worked alone on all stages of the product.
This was a personal project, and I worked alone on all stages of the product.
Education
2012 - 2016
Bachelor's Degree in Mathematics and Computer Science
Technical University of Cluj Napoca - Cluj-Napoca, Romania
Skills
Libraries/APIs
RxJava, RxJava 2, REST APIs
Tools
Android Studio, Android Jetpack, Gradle, WebView, Android NDK, Jira, Jenkins, Charles, Confluence, ExoPlayer, Figma, Spreadsheets, Apache Maven, MATLAB, Microsoft Excel, Sentry, Codecov, Grafana
Languages
Java, Kotlin, Dart, C++, GraphQL
Frameworks
Android SDK, Dagger, Dagger 2, Flutter
Paradigms
Class-based OOP, Object-oriented Programming (OOP), Agile, Mobile Development, Clean Architecture, Model View ViewModel (MVVM), Application Lifecycle Management (ALM), Continuous Integration (CI), Test-driven Development (TDD), Unit Testing, Cross-platform
Platforms
Android, Mobile, Arduino, Firebase, Bluetooth Low Energy (LE), MacOS, Windows, New Relic, Google Ads, Leanplum, Amazon Web Services (AWS)
Storage
Cloud Firestore, Databases, MySQL
Industry Expertise
Telecommunications
Other
Push Notifications, Authentication, Mobile App Development, Minimum Viable Product (MVP), APIs, Mobile Apps, Google Play Store, User Experience (UX), User Interface (UI), Debugging, GitHub Actions, Mobile Applications, Data Modeling, Android Development, SSL, SSL Certificates, Breadboarding, Integration Testing, Coroutines, SMS, WebSockets, Bluetooth, Smart Devices, Internet of Things (IoT), QR Codes, Android Animations, Subscriptions, Jetpack Compose, Kotlin Multiplatform, Kotlin Multiplatform Mobile (KMM), Scalability, Large-scale Projects, CI/CD Pipelines, Electrical Engineering, Engineering, Data Structures, Embedded Java, Education, Video Streaming, Controls, Java Native Interface (JNI)
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