Roman is available for hire
Hire RomanRoman Tikonov
Verified Expert in Engineering
Software Developer
Location
Munich, Bavaria, Germany
Toptal Member Since
August 13, 2019
Roman is a senior Android developer, proficient in Kotlin, Java, Android, and modern app dev frameworks. He is experienced in building large-scale mobile applications with modular architecture with millions of users and more than 100,000 lines of code, automating build, testing, and release processes. Roman always communicates clearly and transparently, and he can jump in and be productive from day one of the project.
Portfolio
Independent Work
Model View ViewModel (MVVM), Model View Presenter (MVP), Android Jetpack...
MediaMarkt Saturn
Room, LiveData, Dagger 2, RxJava, Kotlin, Android SDK, Scrum, Mockito...
Simplinic GmbH
Sketch, Java, Android, Android SDK, Kanban, REST APIs, Gradle, SOLID Principles...
Experience
Availability
Part-time
Preferred Environment
Kotlin, Git, Android Studio, MacOS, Agile
The most amazing...
...project was to rebuild an app of the largest European electronics retailer with a modular architecture, automated tests, and CI, improving the app's tech KPIs.
Work Experience
Senior and Lead Android Developer
2018 - PRESENT
Independent Work
- Developed several native Android apps using Kotlin, Coroutines, channels and flows, RxJava 2, Dagger2, ViewModel and LiveData, and other components from Android Jetpack.
- Consulted large German and international enterprises: BMW, AutoScout24, Eurowings, IBM, and ING-DiBa.
- Modularised large native apps to speed up development, decouple app areas from each other, and improve code structure.
- Led an Android development team and supervised other developers.
- Applied architecture and design patterns like clean architecture, MVP, MVVM, and MVI.
- Migrated a legacy app to a new dependency injection framework.
- Contributed to the development of the apps with millions of active users.
Technologies: Model View ViewModel (MVVM), Model View Presenter (MVP), Android Jetpack, Dagger 2, RxJava, Kotlin, Android Architecture Components, Coroutines, Android SDK, Scrum, Kanban, Mockito, REST APIs, Gradle, SOLID Principles, Unit Testing, Continuous Integration (CI), Gang of Four (GOF) Design Patterns, Espresso, Clean Architecture, Agile
Senior Consultant Android Development
2017 - 2018
MediaMarkt Saturn
- Completely rebuilt a large-scale legacy B2C app with millions of users using Kotlin.
- Migrated the app to a new modular app architecture and applied clean architecture, MVP, and MVVM.
- Set up continuous integration pipeline from scratch using Jenkins.
- Integrated various Firebase services into the app.
- Supervised and mentored junior developers in the Android team.
Technologies: Room, LiveData, Dagger 2, RxJava, Kotlin, Android SDK, Scrum, Mockito, REST APIs, Gradle, SOLID Principles, Unit Testing, Continuous Integration (CI), Gang of Four (GOF) Design Patterns, Espresso, Agile
Co-founder | Chief Product Officer | Lead Android Developer
2016 - 2017
Simplinic GmbH
- Created UX concepts of several mobile apps, including user flows, wireframes, and graphical design.
- Architected and developed several Android apps from scratch.
- Developed performance-optimized custom 2D indoor map capable of showing hundreds of objects simultaneously.
- Integrated RESTful services into native Android apps.
- Acted as a product owner of web apps in a Scrum-based setting.
Technologies: Sketch, Java, Android, Android SDK, Kanban, REST APIs, Gradle, SOLID Principles, Unit Testing, Gang of Four (GOF) Design Patterns
Technical Product Manager
2013 - 2016
Payoneer
- Managed customer self-care web portal for Payoneer Germany.
- Created concepts for new features, including feature specs and UI mock-ups.
- Designed RESTful APIs for new features of the self-service portal.
- Supervised development and QA processes in a Scrum team.
- Reported directly to the CEO and the head of product.
Technologies: Java, Scrum, REST APIs, SOLID Principles, Unit Testing, Gang of Four (GOF) Design Patterns
Android Developer
2012 - 2012
Greenrobot
- Developed features for native Android applications.
- Created native app widgets for device home screen.
- Integrated Facebook mobile SDK into a TV-guide app.
- Implemented scalable phone and tablet screen layouts.
Technologies: Java, Android, Android SDK, Gradle, SOLID Principles, Unit Testing, Gang of Four (GOF) Design Patterns
Co-founder | Android Developer
2011 - 2011
SurfStudio
- Developed native Android apps using agile methodologies.
- Worked in all phases of a product dev cycle, including requirements engineering, UI prototyping, implementation, and testing.
- Released a new app version for a large American retailer of home renovation products.
- Developed an application to manage personal finances.
- Implemented bidirectional database sync between an Android app and a back end.
Technologies: Java, Android, Android SDK, SOLID Principles, Unit Testing, Gang of Four (GOF) Design Patterns
Experience
Online Banking App
I contributed to a native Android app of the largest German-European online bank by streamlining and updating a customer onboarding flow, improving accessibility, and consulting on material design guidelines.
AutoScout24
https://www.autoscout24.de/A native Android app of the largest European Online Marketplace of Used Cars.
Accomplishments:
• Migrated more than 100,000 lines of code codebase to Dagger 2 DI framework
• Implemented push notifications
• Implemented background processing using Work Manager
• Implemented A/B tests
• MVI architecture, Kotlin, RxJava2
Accomplishments:
• Migrated more than 100,000 lines of code codebase to Dagger 2 DI framework
• Implemented push notifications
• Implemented background processing using Work Manager
• Implemented A/B tests
• MVI architecture, Kotlin, RxJava2
Healthcare app for a health insurance company
A native greenfield app for one of the largest German public health insurance companies.
I was a lead developer. I have interviewed new candidates and assembled a team of four Android devs. Discussed and defined an app architecture. Developed several app features, including digital vaccination certificates.
I was a lead developer. I have interviewed new candidates and assembled a team of four Android devs. Discussed and defined an app architecture. Developed several app features, including digital vaccination certificates.
Eurowings Airline App
https://play.google.com/store/apps/details?id=com.germanwings.androidOne of the top three largest budget European airlines.
Hybrid Android app in native and WebView. I proactively promoted and initiated codebase migration from Java to Kotlin, introduced new layered architecture with separation of concerns, worked on accessibility, and migrated several features from WebView to a native implementation.
Hybrid Android app in native and WebView. I proactively promoted and initiated codebase migration from Java to Kotlin, introduced new layered architecture with separation of concerns, worked on accessibility, and migrated several features from WebView to a native implementation.
MediaMarkt eCommerce App
https://play.google.com/store/apps/details?id=com.media.marktThe largest European electronics retailer.
As a senior developer in a scrum team, I have fostered a gradual rewrite and modernization of the existing eCommerce app:
• Migrated the legacy B2C app from Java to Kotlin
• Introduced to new modular app architecture (Gradle feature modules, architecture layers). Clean architecture, MVP, MVVM
• Performance optimization, automated testing, continuous integration
As a senior developer in a scrum team, I have fostered a gradual rewrite and modernization of the existing eCommerce app:
• Migrated the legacy B2C app from Java to Kotlin
• Introduced to new modular app architecture (Gradle feature modules, architecture layers). Clean architecture, MVP, MVVM
• Performance optimization, automated testing, continuous integration
BMW Connected Motorbike App
• Started migration of a Java codebase to Kotlin
• Introduced MVVM design pattern with ViewModel and LiveData
• Developed custom UI components and dashboards
• Supervised junior developers
• Worked in a Scrum environment
• Introduced MVVM design pattern with ViewModel and LiveData
• Developed custom UI components and dashboards
• Supervised junior developers
• Worked in a Scrum environment
Object Tracking in Hospital
• Designed and implemented the mobile app from scratch
• Implemented real-time location tracking of all moving objects within the hospital building, with search and filter functions
• Implemented performance-optimized custom indoor map
• Implemented real-time location tracking of all moving objects within the hospital building, with search and filter functions
• Implemented performance-optimized custom indoor map
Bed Process Management in Hospital
Real-time location tracking and status overview of patient beds for hospital employees.
Highlights: RESTful JSON API, IoT Bluetooth Client, Smartphone and Tablet App designed and developed from scratch.
Highlights: RESTful JSON API, IoT Bluetooth Client, Smartphone and Tablet App designed and developed from scratch.
Dementia Patients Monitoring in Hospital
Real-time location tracking of patients with memory problems and alarm notifications for hospital employees.
Highlights: Alarm monitoring in background, guaranteed real-time alarm delivery via message queue protocol
Highlights: Alarm monitoring in background, guaranteed real-time alarm delivery via message queue protocol
Shouts: Audio Messenger for Youth
Developed an audio messenger for teenagers and young adults from scratch.
Particularly complex parts: transport and delivery of audio messages, storage and playback of audio files, push notifications, and integration with Facebook apps.
Particularly complex parts: transport and delivery of audio messages, storage and playback of audio files, push notifications, and integration with Facebook apps.
EverCare
Visualization of crime levels for the city of London, location of family members, and a call-for-help function.
Highlights: customized 2D map with overlays of crime activity, RESTful JSON API, and big data visualization.
Highlights: customized 2D map with overlays of crime activity, RESTful JSON API, and big data visualization.
Prime Guide TV schedule
https://play.google.com/store/apps/details?id=de.greenrobot.tvguideThe app shows complex data like the TV schedule of multiple TV channels across configurable timespan in a simple, easy-to-grasp manner on a limited space of a mobile phone screen.
Contributed to the development of a TV schedule app:
• Implemented scalable, reusable smartphone and tablet layouts
• Integrated Facebook SDK into the app
• Implemented a home screen widget
Contributed to the development of a TV schedule app:
• Implemented scalable, reusable smartphone and tablet layouts
• Integrated Facebook SDK into the app
• Implemented a home screen widget
Personal Finance App
https://play.google.com/store/apps/details?id=ru.surfstudio.personalfinanceAn app for personal expenses management that allows tracking income, expenses, and showing reports.
Implemented bidirectional client-server data synchronization with conflict resolution strategies to solve concurrent editing from mobile and web apps.
Also developed several application screens.
Implemented bidirectional client-server data synchronization with conflict resolution strategies to solve concurrent editing from mobile and web apps.
Also developed several application screens.
Education
2011 - 2014
Master of Science Degree in Informatics
Technische Universität München - Munich, Germany
2012 - 2013
Honours Degree in Technology Management
Center for Digital Technology & Management - Munich, Germany
2006 - 2011
Diploma in Computer Science
Voronezh State University - Voronezh, Russia
Certifications
FEBRUARY 2018 - PRESENT
Certified Product Owner
scrum.org
Skills
Libraries/APIs
RxJava 2, Retrofit 2, REST APIs, RxKotlin, Android Architecture Components, RxJava, LiveData, Jenkins Pipeline, Google Maps SDK, Picasso
Tools
Android Jetpack, Android Studio, Git, Gradle, Jira, Confluence, Sketch, Jenkins, Firebase Test Lab, Optimizely, RxAndroid
Frameworks
Dagger 2, Android SDK, Espresso, Mockito
Paradigms
Clean Architecture, Scrum, Agile, Model View Presenter (MVP), Model View ViewModel (MVVM), Model View Intent (MVI), Kanban, Unit Testing, Continuous Integration (CI), Gang of Four (GOF) Design Patterns, Clean Code, Management
Languages
Kotlin, Java
Platforms
Android, Firebase, MacOS
Storage
RoomDB, JSON, SQLite, Cloud Firestore
Other
GitFlow, SOLID Principles, Room, Material Design, Coroutines, Product Development, Entrepreneurship, Leadership, OpenID Connect (OIDC), Technology
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