Roman Tikonov, Developer in Munich, Bavaria, Germany
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Roman Tikonov

Verified Expert  in Engineering

Software Developer

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.


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...




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
  • 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
  • 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
  • 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

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.

A native Android app of the largest European Online Marketplace of Used Cars.
• 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.

Eurowings Airline App
One 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.

MediaMarkt eCommerce App
The 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

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

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

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.

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

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.


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.

Prime Guide TV schedule
The 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

Personal Finance App
An 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.
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


Certified Product Owner


RxJava 2, Retrofit 2, REST APIs, RxKotlin, Android Architecture Components, RxJava, LiveData, Jenkins Pipeline, Google Maps SDK, Picasso


Android Jetpack, Android Studio, Git, Gradle, Jira, Confluence, Sketch, Jenkins, Firebase Test Lab, Optimizely, RxAndroid


Dagger 2, Android SDK, Espresso, Mockito


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


Kotlin, Java


Android, Firebase, MacOS


RoomDB, JSON, SQLite, Cloud Firestore


GitFlow, SOLID Principles, Room, Material Design, Coroutines, Product Development, Entrepreneurship, Leadership, OpenID Connect (OIDC), Technology

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