Vitaly Goncharuk

A microservices-based platform for business process automation of a global retail company. The platform increased company effectiveness and reduced the number of required employees. It served up to 300,000 active users/day and had a daily turnover of up to $1 million.

I was a tech lead and worked on the back-end architecture and business logic implementation, which included the following:
• Customer payment process
• Affiliated sales
• Complex logic of payment transaction processing with multiple payment providers
• Multi-user administration panel
• Smart disputes and chargeback management
• Control panel for supporters
• Internationalization
• Plural sales reports
• Refund processing
• Statistics
• Smart bulk mailing
• Product management
• Data import and export
• Complex pricing formation logic
• URL shortener service
• User behavior tracking
• After-sale customers' panel
• Affiliates dashboard
• Complex logic for different currencies and countries
• SMS and Viber notifications
• Webhooks processing from multiple SaaS entities
• Multi-template front end
• Integration of third-party services
• API for external services
• Monitoring of platform status, shipments, Facebook comments, and staff work quality
• High-load optimization

A React-based web app with a PHP back end to help people monitor and improve their health. Using special algorithms, it suggests the best daily recipes for users based on many parameters.

I was the tech lead and worked on the back-end architecture and business logic implementation, which included the following:
• Smart personal meal plan generation
• Support of two measurement systems
• Recipe and ingredient filters
• Shopping list
• Water tracker
• Blog functionality
• Customer payment process
• Affiliated sales
• Complex logic of payment transaction processing with multiple payment providers
• Multi-user administration panel
• Internationalization
• Sales reports
• Refund processing
• Statistics
• Smart bulk mailing
• Different subscription types
• Data imports
• Ad code integration and management
• Complex pricing formation logic
• Users' behavior tracking
• Affiliates dashboard
• Complex logic for different currencies and countries
• Multi-template front end
• Integration of third-party services (Google APIs, PayPal, Stripe, ThriveCart, AWS SDK, and Sentry)
• API for external services
• User data validation
• High-load optimization
• Vertical sharding
• Data replication
• Data caching
• Front-end speed optimization

A Google Polymer-based multiplayer browser online game with a Node.js back-end developed using Ethereum blockchain technologies. The game was played by 1,000 daily active users who had ETH, and the maximum daily turnover was 3,000 ETH (more than US$3 million in those days).

I was a lead back-end developer and worked on back-end architecture and business logic implementation, which included the following:
• API
• Authentication
• User data processing
• Mathematical calculations
• Game logic
• Internationalization
• Statistics
• Ratings
• High-load optimization
• Web3.js integration
• Monitoring of game smart contract events
• Sending transactions to the blockchain
• Control of duplication
• Order of execution and errors for transactions
• Nonce management
• Gas pricing for outgoing transaction management
• Safe resends of failed transactions
• Self-checks for server health statuses
• Safe server deployment

I participated in the development of several multiplayer logical game apps where users solve different types of puzzles for further progress. The games were developed for mobile platforms (Android, iOS, and Blackberry), and the back-end API was based on PHP frameworks.

I worked on these projects as a lead back-end developer and built the back-end architecture and business logic implementation, which included the following:
• API
• Authentication
• User data processing
• User sessions
• Validation of input data
• Game logic
• Push notifications
• Statistics
• Ratings
• In-app purchases
• High-load optimization
• Data caching
• Control panel
• Self-checks for server health statuses

I contributed to the builds of several multiplayer city-builder game apps using a variety of tech stacks and individual designs, rules, and logic. However, they all had a common idea and a playing strategy: users need to grow their own empire (city, amusement park, restaurant, and so on) by solving economic, managerial and financial tasks.

The games were developed for mobile platforms (Android, iOS, and Blackberry), and the back-end APIs were created using PHP and Node.js. The most popular game had up to 100,000 active users a day and 40 million players in total, and the biggest tables have more than 1 billion records.

I was a lead back-end developer and worked on back-end architecture and business logic implementation, which included the following:
• API
• Authentication
• User data processing
• User sessions
• Validation of input data
• Game logic
• Internationalization
• Push notifications
• Statistics
• Ratings
• Integration of third-party services (Facebook, Google Play, Amazon, and Tapjoy)
• In-app purchases
• High-load optimization
• Horizontal and vertical sharding
• Data replication
• Data caching
• Control panel
• Self-checks for server health statuses

DrawMania won the Best Social Mobile Game of the Year award from the International Mobile Gaming Awards (IMGA, Barcelona). The app was preinstalled on the Samsung Galaxy Note II in some countries and had up to 10 million users in total.

It's a multiplayer game app where a player draws a suggested word or guesses a word drawing by other users. The game was developed for mobile (Android, iOS, and Blackberry) and browser (apps inside popular social networks) platforms, and the back-end API was based on a PHP framework.

I was a tech lead and worked on the back-end architecture and business logic implementation, which included the following:
• API
• Authentication
• User data processing
• Validation of input data
• Game logic
• Push notifications
• Statistics
• Ratings
• Internationalization
• In-app purchases
• Integration of third-party services (Facebook, OK, and VK)
• High-load optimization
• Data caching
• Self-checks for server health statuses
• Control panel

A browser-based web platform for project management and team collaboration that was developed using a PHP framework.

I was a tech lead and worked on the back-end architecture and business logic implementation, which included the following:
• Authentication
• User data processing
• User sessions
• Validation of input data
• Processing of media files (photos, videos)
• User activity
• Feeds
• Search
• Internationalization
• Chats
• User management
• Statistics
• Integration of third-party services (Facebook, Twitter, Gmail, YouTube, and PayPal)
• High-load optimization
• Data caching
• Control panel

We built several browser web platforms with wide and powerful social network functionality while considering clients' custom requirements. It was developed using a PHP framework.

I was a senior back-end developer and worked on business logic implementation, which included the following:
• Authentication
• User data processing
• User sessions
• Validation of input data
• Media files (photo and video)
• User activity
• Feeds
• Search
• Chats
• Internationalization
• Friend functionality
• Blogs
• Project-specific features
• User management
• Statistics
• Integration of third-party services (Facebook, Twitter, Gmail, Yahoo, and YouTube)
• High-load optimization
• Data caching
• SQL query optimization

An eCommerce platform with custom requirements that allows the client to launch highly and easily customizable online stores. It was developed using a PHP framework.

I was a senior back-end developer and worked on business logic implementation, which included the following:
• Authentication
• User data processing
• Validation of input data
• Internationalization
• Integration of third-party services (Yandex Market, Google, and PayPal)
• Shopping basket
• Support of different currencies
• Data exports and imports
• Data caching
• Control panel

A logical game using the Telegram Bot platform where a player solves puzzles to earn in-game points, and their progress is shown in leaderboards. The back-end API was developed using Node.js.

I was a senior back-end developer and worked on business logic implementation, which included the following:
• Telegram API integration
• Authentication
• User data processing
• Validation of input data
• Internationalization
• Data exports and imports
• Data caching, search filters
• High-load optimization
• Control panels

A custom CMS built according to a client's requirements with multiple functions for easy use. It was developed using a PHP framework.

I was a back-end developer and worked on many features, which included the following:
• Authentication
• User data processing
• Validation of input data
• Internationalization
• Data exports and imports
• Data caching
• Search filters
• High-load optimization
• Control panels