Anton Efimenko, Developer in Moscow, Russia
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Anton Efimenko

Verified Expert  in Engineering

iOS Developer

Moscow, Russia
Toptal Member Since
June 6, 2019

Anton is an experienced developer who has worked both for large and small companies. After a decade of supporting CAD systems as a .NET developer, he switched to mobile and now specializes in iOS development. Anton joined Toptal to find exciting and challenging tasks and opportunities for continuous improvement.


Swift, iOS, CI/CD Pipelines, TeamCity, Streaming
Stochastic Systems LLC (via Toptal)
Swift, iOS, WebRTC, UIKit, Bash, AVFoundation
Alpina Digital
CocoaPods, React Native, RxSwift, ES6 Promises, AsyncDisplayKit, Realm, Swift...




Preferred Environment

Git, Carthage, CocoaPods, Swift, Xcode, MacOS

The most amazing...

...thing I've coded is my own Redux implementation for iOS using functional reactive programming.

Work Experience

iOS Developer

2021 - 2021
  • Implemented Continuous Deployment pipeline for the application using fastlane and TeamCity server. Also configured and built servers.
  • Worked on the "Live Stream" feature, which allows users to do live streams (solo or groups up to nine people). Implemented UI and DSK integration.
  • Collaborated on code refactoring (moving generic code into submodules), submodule, and dependency modifications to allow the app to compile with Bitcode. Performed code review.
Technologies: Swift, iOS, CI/CD Pipelines, TeamCity, Streaming

iOS Developer

2020 - 2021
Stochastic Systems LLC (via Toptal)
  • Redesigned the whole application using new mockups.
  • Fixed application bugs, including memory issues and WebRTC communication.
  • Supported existing integration tests and wrote new tests for redesigned screens.
Technologies: Swift, iOS, WebRTC, UIKit, Bash, AVFoundation

Senior iOS Developer

2019 - 2020
Alpina Digital
  • Implemented a video player for online education courses and supported streaming playback and playlists.
  • Supported a CI pipeline and implemented new conditional builds for different customers.
  • Created a statistics module used to gather usage statistics, e.g., how long a user read a book, watched a video, or listened to an audiobook.
  • Managed the submitting and approval process to the App Store.
Technologies: CocoaPods, React Native, RxSwift, ES6 Promises, AsyncDisplayKit, Realm, Swift, Xcode, Cocoa Touch, Swift 4, Fastlane, Mobile Architecture, REST APIs, Agile, Continuous Deployment, Docker, Bash, Docker Compose, Charles Proxy, TeamCity, AVFoundation, ReSwift, Agile Software Development, iOS, Push Notifications

Senior iOS Developer

2018 - 2019
  • Implemented new an in-app chat using WebSockets (replacement for old chat that used HTTP GET for updates).
  • Worked on referral program feature. Added new screens for referral program management.
  • Supported the company's CI server for mobile applications.
  • Reworked a mobile app's startup logic to allow the fastest startup, which also reduced the app's download size.
  • Implemented in-app calls using VoxImplant iOS framework.
  • Managed App Store submitting and approval process.
  • Reworked massive storyboard into xibs (one per screen).
Technologies: CocoaPods, Git, Core Data, RxSwift, WebSockets, iOS, Swift, Xcode, Cocoa Touch, Swift 4, Fastlane, REST APIs, Agile, Jira, Bash, Charles Proxy

Senior iOS Developer

2016 - 2018
  • Developed a synchronization module for a POS application.
  • Implemented an adaptive interface for the iPad version of the POS application.
  • Wrote UI automation tests using the Appium SDK for cross platform testing.
  • Managed a small team of three developers (including myself).
  • Created various reusable UI components for mobile applications.
  • Developed calculation logic for discounts in POS App.
  • Built a wrapper around a C library for a receipt printer (for a POS application).
Technologies: Carthage, CocoaPods, Git, RxSwift, Realm, iOS, Swift, Xcode, Cocoa Touch, Swift 4, iPad, Fastlane, REST APIs, GitHub, Jira, Bash, ReSwift, Agile Software Development

Senior Engineer

2007 - 2016
  • Created a customizable data loader for SmartPlant Foundation.
  • Developed a custom data-mapping tool used for loading assets from SmartPlant P&ID into SmartPlant Foundation (with the ability to specify custom properties and relations between objects).
  • Built and supported a variety of client and server API for SmartPlant Foundation.
  • Created a data-synchronization tool used for automatic nightly syncs between two SPF servers.
  • Developed a custom abstraction layer around default SPF API using Castle Dynamic Proxy.
Technologies: Oracle, Microsoft SQL Server, .NET, Windows, C#


Petstory is a veterinary service that allows users to make an appointment with a veterinarian in a clinic or through a video call.

I developed the new chat and video conference system version with improved stability and performance.

Technologies: Swift, Core Data, WebSockets


MoySklad is an iOS client to a SaaS service allowing users to manage their accounts, create and modify various types of documents, manage goods, storehouses, and so on.

I was involved in developing various parts of the application. I implemented the generic UI and business logic for managing 20+ different types of documents.

Technologies: Swift 4.2, Alamofire, SnapKit, RxSwift, JSON, Redux

MoySklad POS

MoySklad POS is a point-of-sale application for retail. The app can work without an internet connection and upload all operations to the cloud when it becomes online.

Technologies: Swift 4.2, Alamofire, SnapKit, RxSwift, Realm Database, Redux

Desktop (macOS) Player for Google Music
I built this desktop application for listening to radio stations via Google Play Music using Swift, RxSwift, and Redux. It's quite a simple application that uses Google Music API to load and stream music (this API is already deprecated).

Aika | Simple Task Manager

Aika is a task manager for iOS (iPhone and iPad) similar to a native iOS application. It has an offline mode, synchronization, and push notifications.

Technologies: Swift, Realm, RxSwift, Auth0 (Authentication), OneSignal (Push Notifications)

Alpina Digital Library

Alpina Digital Library is an app for reading books, listening to audiobooks, and watching learning video courses.

I developed a new module for video courses, including UI for new screens, video player with custom queue and usage tracking.


LYKA is a free social media platform allowing users to connect, discover new things, and share their interests with others.

I worked mainly on the live-streaming feature and integrated SDK for live streaming. I also implemented UI for single and multi-guest modes (up to nine live streamers).
2004 - 2009

Master's Degree in Computer Science

Moscow University for Industry and Finance "Synergy" - Moscow, Russia


Microsoft® Certified Technology Specialist: .NET Framework 4, Service Communication Applications



Microsoft Certified Professional



Microsoft® Certified Technology Specialist: .NET Framework 4, Data Access



REST APIs, RxSwift, SnapKit, Codable, CocoaPods, Fabric, WebRTC, ReSwift, Alamofire


Xcode, Auto Layout, iTunes Connect, Travis CI, Git, GitHub, Charles Proxy, Interface Builder, Microsoft Visual Studio, Crashlytics, Fastlane, Docker Compose, TeamCity, AsyncDisplayKit, GitLab, Bitbucket, Amazon Elastic Container Service (Amazon ECS), Auth0, Firebase Analytics, Zeplin, Jira, Confluence, Jenkins, Docker Swarm


UIKit, Cocoa Touch, Viper, RealmSwift, XCTest, .NET, Core Data, React Native, Vapor, .NET Core, Entity Framework Core, ASP.NET Web API, AppKit, Cocoa, Appium, XCUITest


Swift, C#, Swift 2, Swift 3, Swift 4, Swift 5, SQL, Bash, Bash Script


Agile Software Development, VIPER Architecture, Functional Programming, Functional Reactive Programming, Unit Testing, Model View ViewModel (MVVM), Dependency Injection, Agile, REST, Continuous Integration (CI), Continuous Deployment, Test-driven Development (TDD)


iOS, Windows, MacOS, Docker, Amazon EC2, Bitrise, Keychain, Oracle, Kubernetes, Firebase, Oracle Database, Amazon Web Services (AWS)


JSON, Realm, PostgreSQL, Amazon S3 (AWS S3), Microsoft SQL Server


Mobile Architecture, Carthage, iPhone, Push Notifications, Storyboarding, iPad, ES6 Promises, UI Testing, AVFoundation, WebSockets, CI/CD Pipelines, Streaming

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